Answer:
$57
Since $71.25 was paid for working 7.5 hours.
That means he was being paid $9.5 per hour.
Which is 71.25÷7.5.
And on tuesday that's 9.5×6 which is $57
I need help with this !!
Answer:
A
Step-by-step explanation:
When subtracting 7 on the left of the equation, he also needs to subtract 7 from the right of the equation.
Step 2 should be:
⅓X +7 -7= 15 -7
What he is trying to do here by subtracting 7 is to move all the constants, that is numbers without any variables such as x, to one side of the equation.
⅓X= 8
X= 8 ×3
X= 24
Hi I need this question please asap.
PLEASE HELP QUICK! Determine x value of: sqrt x + 8 - sqrt x - 4 = 2
Answer:
x=8
Step-by-step explanation:
[tex]\sqrt{x+8}-\sqrt{x-4}=2\\\sqrt{x+8}=2+\sqrt{x-4}\\\left(\sqrt{x+8}\right)^2=\left(2+\sqrt{x-4}\right)^2\\x+8=x+4\sqrt{x-4}\\8=4\sqrt{x-4}\\8^2=\left(4\sqrt{x-4}\right)^2\\64=16x-64\\x=8[/tex]
In a soccer league, the ratio of boys to girls is 4 to 6. There are a total of 50 players in the soccer league. Determine how many girls play in the soccer league.
Answer:
30
Step-by-step explanation:
We can call the number of boys 4x and girls 6x so we can write:
4x + 6x = 50
10x = 50
x = 5, therefore the number of girls is 6x = 6 * 5 = 30.
Answer:
30
Step-by-step explanation:
In the ratio 4:6, we can think of this like 4 boys and 6 girls out of 10 team members.
We can find how many girls play by multiplying 6 by 5, since 50 divided by 10 is 5.
6(5) = 30, so 30 girls play in the soccer league.
The circumference of the base of a cylinder is 24π mm. A similar cylinder has a base with circumference of 60π mm. The lateral area of the larger cylinder is 210π mm2. What is the lateral area of the smaller cylinder? 17.1π mm2 33.6π mm2 60π mm2 84π mm2
Answer:
84π mm^2
Step-by-step explanation:
formula for circumference is 2πr where r is the radius of circle
Given,The circumference of the base of a cylinder is 24π mm
Thus,
2πr= 24π mm
=> r = 24π mm/2π = 12 mm
________________________________________
A similar cylinder has a base with circumference of 60π mm.
radius for this cylinder will be
2πr= 60π mm
r = 60π mm/2π = 30mm
______________________________________________
Given
The lateral area of the larger cylinder is 210π mm2
lateral area of cylinder is given by 2πrl
where l is the length of cylinder
thus,
r for larger cylinder = 30mm
2π*30*l = 210π mm^2
=> l = 210π mm^2/2π*30 = 3.5 mm
___________________________________________
the lateral area of the smaller cylinder
r = 12 mm
l = 3.5 mm as both larger and smaller cylinder are same
2πrl = 2π*12*3.5 mm^2 = 84π mm^2 answer
Answer:
33.6pi mm2 is the correct answer
edge 2021
Step-by-step explanation:
The circumference of the base of a cylinder is 24π mm. A similar cylinder has a base with circumference of 60π mm. The lateral area of the larger cylinder is 210π mm2.
What is the lateral area of the smaller cylinder?
17.1π mm2
33.6π mm2
60π mm2
84π mm2
Determine the t critical value for a lower or an upper confidence bound in each of the following situations. (Round your answers to three decimal places.)
a. Confidence level = 95%, df = 10
b. Confidence level = 95%, df = 15
c. Confidence level = 99%, df = 15
d. Confidence level = 99%, n = 5
e. Confidence level = 98%, df = 23
f. Confidence level = 99%, n = 32
Answer:
A. 1.812
B. 1.753
C. 2.602
D. 3.747
E. 2.069
F. 2.453
Step-by-step explanation:
A. 95% confidence level, the level of significance = 5% or 0.05
Using t-table, the critical value for a lower or an upper confidence bound at 0.05 significance level with 10 degrees of freedom = 1.182
B. 95% confidence interval = 0.05 level of significance
Using t-table, the critical value for a lower or an upper confidence bound at 0.05 significance level with 15 degrees of freedom = 1.753
C. 99% confidence interval = 0.01 level of significance
Using t-table, the critical value for a lower or an upper confidence bound at 0.01 significance level with 15 degrees of freedom = 2.602
D. 99% confidence interval = 0.01 level of significance; DF (n - 1) = 5- 1 = 4
Using t-table, the critical value for a lower or an upper confidence bound at 0.01 significance level with 4 degrees of freedom = 3.747
E. 98% confidence interval = 0.02 level of significance
Using t-table, the critical value for a lower or an upper confidence bound at 0.02 significance level with 23 degrees of freedom = 2.069
F. 99% confidence interval = 0.01 level of significance; df (n - 1) = 32 - 1 = 31
Using t-table, the critical value for a lower or an upper confidence bound at 0.01 significance level with 31 degrees of freedom = 2.453
Find the probability of each event. A six-sided die is rolled seven times. What is the probability that the die will show an even number at most five times?
Answer:
[tex]\dfrac{15}{16}[/tex]
Step-by-step explanation:
When a six sided die is rolled, the possible outcomes can be:
{1, 2, 3, 4, 5, 6}
Even numbers are {2, 4, 6}
Odd Numbers are {1, 3, 5}
Probability of even numbers:
[tex]\dfrac{\text{Favorable cases}}{\text{Total cases }} = \dfrac{3}{6} = \dfrac{1}{2}[/tex]
This is binomial distribution.
where probability of even numbers, [tex]p =\frac{1}{2}[/tex]
Probability of not getting even numbers (Getting odd numbers) [tex]q =\frac{1}{2}[/tex]
Probability of getting r successes out of n trials:
[tex]P(r) = _nC_r\times p^r q^{n-r}[/tex]
Probability of getting even numbers at most 5 times out of 7 is given as:
P(0) + P(1) +P(2) + P(3) +P(4) + P(5)
[tex]\Rightarrow _7C_0\times \frac{1}{2}^0 \frac{1}{2}^{7}+_7C_1\times \frac{1}{2}^1 \frac{1}{2}^{6}+_7C_2\times \frac{1}{2}^2 \frac{1}{2}^{5}+_7C_3\times \frac{1}{2}^3 \frac{1}{2}^{4}+_7C_4\times \frac{1}{2}^4 \frac{1}{2}^{3}+_7C_5\times \frac{1}{2}^5 \frac{1}{2}^{2}[/tex]
[tex]\Rightarrow (\dfrac{1}{2})^7 (_7C_0+_7C_1+_7C_2+_7C_3+_7C_4+_7C_5)\\[/tex]
[tex]\Rightarrow (\dfrac{1}{2})^7 (1+7+\dfrac{7 \times 6}{2}+\dfrac{7 \times 6 \times 5}{3\times 2}+\dfrac{7 \times 6 \times 5}{3\times 2}+\dfrac{7 \times 6}{2})\\\Rightarrow \dfrac{120}{128} \\\Rightarrow \dfrac{15}{16}[/tex]
How to calculate a circumference of a circle?
Answer: Pi multiplied by the diameter of the circle
Step-by-step explanation:
Answer:
The formula for finding the circumference of a circle is [tex]C = 2\pi r[/tex]. You substitute the radius of the circle for [tex]r[/tex] and multiply it by [tex]2\pi[/tex].
Copy the problem, mark the givens in the diagram. Given: CS ≅ HR, ∠CHS ≅ ∠HCR, ∠CSH ≅ ∠HRC, Prove: CR ≅ HS
Help urgently needed
Explanation:
1. CS ≅ HR, ∠CHS ≅ ∠HCR, ∠CSH ≅ ∠HRC — given
2. ∆CRH ~ ∆HSC — AA similarity theorem
3. ∠SCH ≅ ∠RHC — corresponding angles of similar triangles are congruent
4. CH ≅ HC — reflexive property of congruence
5. ∆CRH ≅ ∆HSC — SAS congruence theorem
6. CR ≅ HS — CPCTC
I hope u can understand help asap
i think u can see sho T=5n+20
Answer:
T(n) = 5n + 20
Step-by-step explanation:
1 candy has a mass of 5 g.
n candies have a mass of 5n grams.
The box has a mass of 20 grams.
total mass = mass of candies + mass of box
T(n) = 5n + 20
n T(n)
0 20
25 145
50 270
75 395
100 520
WILL MARK AS BRAINLIEST 4. Suppose there is a card game where you are dealt a hand of three cards. You have already learned that the total number of three-card hands that can be dealt from a deck of 52 cards is: 52C3=52!/49!3! 52C3=22100 Calculate the probability of getting a hand that has exactly two aces in it (A A X). Do this by finding out the number of possible hands that have exactly two aces, and then dividing by the total possible number of three-card hands that is stated above. Part A: Use the multiplication principle to tell the total number of three-card hands (permutations) that can be made with two aces. (2 points) Part B: In the answer from Part I, each two-ace hand got counted twice. For example, A A X got counted as a separate hand from A A X. Since order should not matter in a card hand, these are really the same hand. What is the actual number of two-ace hands (combinations) you can get from a deck of 52 cards?(2 points) Part C: Find the probability of drawing a three-card hand that includes two aces from a deck of 52 cards. Write your answer as a fraction. (2 points)
Answer:
Part A- 6
Part B- 3
Part C- 3/22100
Step-by-step explanation:
Part A-
Use the permutation formula and plug in 3 for n and 2 for k.
nPr=n!/(n-k)!
3P2=3!/(3-2)!
Simplify.
3P2=3!/1!
3P2=6
Part B-
Use the combination formula and plug in 3 for n and 2 for k.
nCk=n!/k!(n-k)!
3C2=3!/2!(3-2)!
Simplify.
3C2=3!/2!(1!)
3C2=3
Part C-
It is given that the total number of three-card hands that can be dealt from a deck of 52 cards is 22100. Use the fact that the probability of something equals the total successful outcomes over the sample space. In this case the total successful outcomes is 3 and the sample space is 22100.
I believe the answer is 3/22100
I honestly suck at probability but I tried my best.
Please help me. The function g(x) is a transformation of f(x). If g(x) has a y-intercept at 3, which of the following functions could represent g(x)?
The graph shows f(x) to have a y intercept at -1, which is where the diagonal line crosses the y axis. We want the y intercept to move to 3. So we must add 4 to the old y intercept to get the new y intercept.
We do this with every single point on f(x) to get g(x) = f(x)+4. This shifts the graph up 4 units.
Translate the following into an algebraic expression: A number is 30% of 20% of the number x.
Answer: 0.06x
Step-by-step explanation:
An algebraic expression is an expression consist of integer constants, variables, and algebraic operations.The given statement: A number is 30% of 20% of the number x.
The required algebraic expression would be:
30% of 20% of x
[tex]=\dfrac{30}{100}\times \dfrac{20}{100}\times x[/tex] [we divide a percentage by 100 to convert it into decimal]
[tex]=\dfrac{6}{100}\times x\\\\=0.06x[/tex]
Hence, the required algebraic expression would be :
0.06x
Fake Question: Should Ujalakhan01 be a moderator? (If you could answer I'd appreciate it haha.)
Real Question: Simplify [tex](a^5*a^4)+(b^2*b^3)-(c^7*c^6)[/tex]
Answer:
[tex]a^9 + b^ 5 + c^{13}[/tex]
Step-by-step explanation:
[tex](a^5 \times a^4)+(b^2 \times b^3) + (c^7 \times c^6)[/tex]
When bases are same and it is multiplication, then add the exponents.
[tex](a^{5+4})+(b^{2+3})+(c^{7+6})[/tex]
[tex](a^9)+(b^ 5) + (c^{13})[/tex]
Apply rule : [tex](a^b)=a^b[/tex]
[tex]a^9 + b^ 5 + c^{13}[/tex]
Answer:
[tex]a^9+b^5-c^{13[/tex]
Step-by-step explanation:
[tex](a^5*a^4) + (b^2*b^3)-(c^7*c^6)[/tex]
When bases are same, powers are to be added.
=> [tex](a^{5+4})+(b^{2+3})-(c^{7+6})[/tex]
=> [tex]a^9+b^5-c^{13[/tex]
need help thanksssssssss
Answer:
Volume: 112 m³.
Surface area: 172 m².
Step-by-step explanation:
The volume is the base times height times length. So, the volume will be 2 * 8 * 7 = 16 * 7 = 112 m³.
The surface area is 2lw + 2lh + 2wh. l = 8; w = 7; h = 2.
2(8)(7) + 2(8)(2) + 2(7)(2) = 2 * 56 + 2 * 16 + 2 * 14 = 112 + 32 + 28 = 112 + 60 = 172 m².
Hope this helps!
Alex has built a garden shed in the shape shown.
(A) Alex plans to paint the outside of the shed, including the roof but not the floor. One can of paint can cover 6m^2 . How many cans of paint will Alex need.
(B)If one can of paint costs $25.50, what will the cost be including 13% tax.
Answer:
A) 22 cans required to paint
B) Including 13% tax, cost of painting = $633.93
Step-by-step explanation:
As we check the figure, we have a composite figure.
Cuboid on the base and a pyramid on the top of it.
To find the area to be painted, we have 4 rectangular faces of cuboid with dimensions 6m [tex]\times[/tex] 3m.
And 4 triangular faces of pyramid with Base = 6m and Height 5m.
So, total area to be painted = 4 rectangular faces + 4 triangular faces
Area of rectangle = Length [tex]\times[/tex] Width = 6 [tex]\times[/tex] 3 = 18 [tex]m^2[/tex]
Area of triangle = [tex]\frac{1}{2}\times Base \times Height =\frac{1}{2}\times 6 \times 5 = 15\ m^{2}[/tex]
Total area to be painted = 4 \times 18 + 4 \times 15 = 72 + 60 = 132 [tex]m^2[/tex]
A) Area painted by 1 can = 6 [tex]m^2[/tex]
Cans required to paint 132 [tex]m^2[/tex] = [tex]\frac{132}{6} = 22\ cans[/tex]
B)
Cost of 1 can = $25.50
Cost of 22 can = $25.50 [tex]\times[/tex] 22 = $561
Including tax of 13% = $561 + $561 [tex]\times \frac{13}{100}[/tex] = $561 + $72.93 = $633.93
So, the answers are:
A) 22 cans required to paint
B) Including 13% tax, cost of painting = $633.93
Four buses carrying 198 students from the same school arrive at a football stadium. The buses carry, respectively 90, 33, 25, and 50 students. One of the students is randomly selected. Let X denote the number of students who were on the bus carrying the randomly selected student. One of the four bus drivers is also randomly selected. Let Y denote the number of students on her bus. a) Which of E[X] or E[Y] do you think is larger
Answer:
E[x] is larger
Step-by-step explanation:
I think E[x] is larger because the expected number of students on the bus of a randomly chosen student is larger.
This is because the higher the number of students present in a bus, the higher the probability that a randomly selected student would have been on that bus.
Whereas, for every driver to be chosen, the probability of any bus being chosen is 1/4 irrespective of the number of students in that particular bus
what’s the opposite of negative two
Answer: The answer is two
Step-by-step explanation: If you look for opposites of a number its either negative or positive. So when the answer is negative, the opposite is positive and if the answer is positive, the opposite is negative.
Answer:
[tex]\boxed{2}[/tex]
Step-by-step explanation:
The opposite of a number is the number that is the same distance from 0 on the number line.
-2 opposite is 2.
Question 3 (5 points)
POINT
-POINT A
POINT B
What are the coordinates of the point labeled B in the graph shown above?
A) (3, 2)
B) (-3,2)
OC) (-2,3)
D) (-2, -3)
Question 4 (5 points)
Answer:
(D) -2,-3
Step-by-step explanation:
From the origin, we can find the current position of point B by counting.
B is 2 to the left of the y-axis, meaning that it's x value is -2.
B is 3 down of the x-axis, making it's y value -3.
Therefore, the coordinates of point B are -2,-3.
Hope this helped!
Answer: (D) -2,-3
Step-by-step explanation:
Find the difference of functions at x= - 3, (g - f)(-3), given f(x) and g(x): g(x) = x^2−15, and f(x) =2x
Answer:
0
Step-by-step explanation:
Solution:-
We are given two functions as follows:
[tex]f ( x ) = x^2 - 15\\\\g ( x ) = 2x[/tex]
We need to determine the composite function defined as ( g - f ) ( x ). To determine this function we need to make sure that both function exist for all real positive value of x.
The function f ( x ) is a quadratic function which has real values for all values of x. Similarly, function g ( x ) is a linear line that starts from the origin. Hence, both functions are defined over the domain ( -∞, ∞ )
We will perform arithmetic operation of subtracting function f ( x ) from g ( x ) as follows:
[tex][ g - f ] ( x ) = g ( x ) - f ( x )\\\\\\( g - f ) ( x ) = x^2 - 15 - 2x\\\\[/tex]
Now evaluate the above determined function at x = -3 as follows:
[tex]( g - f ) ( -3 ) = ( -3 )^2 - 2 ( -3 ) - 15\\\\( g - f ) ( -3 ) = 9 + 6 - 15\\\\( g - f ) ( -3 ) = 0[/tex]
A rectangular parking lot has an area of 7/10 km 2.The width is 1/3 km 2 .What is the length of the parking lot written as a improper fraction ,in kilometers
Answer:
[tex]\dfrac{21}{10}\text{ km}[/tex].
Step-by-step explanation:
It is given that,
Area of rectangular plot [tex]=\dfrac{7}{10}\text{ km}^2[/tex]
Width of rectangular plot [tex]=\dfrac{1}{3}\text{ km}[/tex]
We need to find the length of the parking lot.
We know that,
[tex]\text{Area of rectangle}=length\times width[/tex]
[tex]\dfrac{7}{10}=length\times \dfrac{1}{3}[/tex]
[tex]\dfrac{7\times 3}{10}=length[/tex]
[tex]length=\dfrac{21}{10}[/tex]
Therefore, length of the parking lot is [tex]\dfrac{21}{10}\text{ km}[/tex].
One kind of candy (jelly) sells for $5 a pound and another (chocolate) for $10 a pound. How many pounds of each should be used to make a mixture of 10 pounds of candy (both kinds) that sells for a total $80 (i.e. $8/pound)?
Answer:
chocolate: 6 poundsjelly: 4 poundsStep-by-step explanation:
Let x represent the number of pounds of chocolate in the mix. Then the total price of 10 pounds of mix is ...
10x +5(10 -x) = 80
5x +50 = 80
5x = 30
x = 6 . . . . . . . . pounds of chocolate
10 -x = 4 . . . . . pounds of jelly candy
6 pounds of chocolate and 4 pounds of jelly should be used to make the mixture.
The exact heights of different elephants Choose the correct answer below. A. The data are continuous because the data can only take on specific values. B. The data are discrete because the data can take on any value in an interval. C. The data are discrete because the data can only take on specific values. D. The data are continuous because the data can take on any value in an interval.
Answer:
Option d: The data are continuous because the data can take on any value in an interval.
Step-by-step explanation:
The data are continuous if they can take on any value within a range. In this case study, there are different elephants including small/young ones and big ones/old ones.
Thus, their heights will vary and can take on any value within a particular range.
what is this? 15.8 = d/25
Answer:
395
Step-by-step explanation:
15.8=d/25
multiply both sides by 25 to remove the denominator
25×15.8=d
d=395
Which expressions are equivalent to: 3(−2a - 4)+3a? A: -6a - 12 +3a B: 3a+12 C: none of the above smh
Answer:
AStep-by-step explanation:
3(−2a - 4)+3a
=-6a - 12 +3a
A: -6a - 12 +3a
[tex]hope \: this \: helps[/tex]
Answer:
the answer is A
Step-by-step explanation:
you have to distribute the number 3 throughout the parentheses so (3*-2a-3*4)+3a = -6a-12+3a
An article in Fire Technology, 2014 (50.3) studied the effectiveness of sprinklers in fire control by the number of sprinklers that activate correctly. The researchers estimate the probability of a sprinkler to activate correctly to be 0.7. Suppose that you are an inspector hired to write a safety report for a large ballroom with 10 sprinklers. Assume the sprinklers activate correctly or not independently. (a) What is the probability that all of the sprinklers will operate correctly in a fire
Answer:
probability that all of the sprinklers will operate correctly in a fire: 0.0282
Step-by-step explanation:
In order to solve this question we will use Binomial probability distribution because:
In the question it is given that the sprinklers activate correctly or not independently. The number of outcomes are two i.e. sprinklers activate correctly or not.A binomial distribution is a probability of a success or failures outcomes in an repeated multiple or n times.
Number of outcomes of this distributions are two.
The formula is:
b(x; n, P) = [tex]C_{n,x}*p^{x} * (1 - p)^{n-x}[/tex]
b = binomial probability also represented as P(X=x)
x =no of successes
P = probability of a success on a single trial
n = no of trials
[tex]C_{n,x}[/tex] is calculated as:
[tex]C_{n,x}[/tex] = n! / x!(n – x)!
= 10! / 10!(10-10)!
= 1
According to given question:
probability of success i.e. p = 0.7 i.e. probability of a sprinkler to activate correctly.
number of trials i.e. n = 10 as number of sprinklers are 10
To find: probability that all of the sprinklers will operate correctly in a fire
X = 10 because we have to find the probability that "all" of the sprinklers will operate correctly and there are 10 sprinklers so all 10 of them
So putting these into the formula:
P(X=x) = [tex]C_{n,x}*p^{x} * (1 - p)^{n-x}[/tex]
= C₁₀,₁₀ * 0.7¹⁰ * (1-0.7)¹⁰⁻¹⁰
= 1 * 0.0282 * (0.3) ⁰
= 1 * 0.0282 * 1
P(X=x) = 0.0282
The cost of plastering the 4 walls of a room which is 4m high and breadth one third of its length is Rs. 640 at the rate of Rs. 5/m². What will be the cost of carpeting its floor at the rate of Rs. 250/m².
Answer:
Rs. 32,000
Step-by-step explanation:
height = 4m
let length = x m
breadth = x/3 m
Area of the 4 walls = 2(length × height) + 2(breadth × height)
Area = 2(4×x) + 2(4 × x/3) = 8x + (8x)/3
Area = (32x)/3 m²
1 m² = Rs. 5
The cost for an area that is (32x)/3 m²= (32x)/3 × 5 Rs.
The cost of plastering 4 walls at Rs.5 per m² = 640
(32x)/3 × 5 = 640
(160x)/3 = 640
x = length = 12
Area = (32x)/3 m² = (32×12)/3 = 128m²
The cost of carpeting its floor at the rate of Rs. 250/m²:
= 128m² × Rs. 250/m² = 32,000
The cost of carpeting its floor at the rate of Rs. 250/m² = Rs. 32,000
Ash Lee bought a new Brunswick boat for $17,000. He made a $2,500 down payment on it. The bank's loan was for 60 months. Finance charges totaled $4,900. His monthly payment is:
Answer: $323.33
Step-by-step explanation:
($17,000 + $4,900 - $2,500) ÷ 60 months = $323.33 per month
↓ ↓ ↓
price finance down payment
Identify the correct HYPOTHESES used in a hypothesis test of the following claim and sample data:
Claim: "The average battery life (between charges) of this model of tablet is at least 12 hours."
A random sample of 80 of these tablets is selected, and it is found that their average battery life is 11.58 hours with a standard deviation of 1.93 hours. Test the claim at the 0.05 significance level.
a. H0: p = 12 vs. H1: p < 12
b. H0: ? = 12 vs. H1: ? < 12
c. H0: p = 12 vs. H1: p > 12
d. H0: ? = 12 vs. H1: ? > 12
Answer:
The null hypothesis is ;
H0 ≥ 12
While the alternative hypothesis H1 is ;
H1 < 12
Step-by-step explanation:
Here, we want to correctly identify the null hypothesis H0 and the alternative hypothesis H1
The null hypothesis is as follows ;
H0 ≥ 12
While the alternative hypothesis H1 is ;
H1 < 12
The amount of time to complete a physical activity in a PE class is approximately normally normally distributed with a mean of 32.9 seconds and a standard deviation of 6.4 seconds.
A) What is the probability that a randomly chosen student completes the activity in less than 33.2 seconds?
B) What is the probability that a randomly chosen student completes the activity in more than 46.6 seconds?
C) What proportion of students take between 35.5 and 42.8 seconds to complete the activity?
D) 75% of all students finish the activity in less than____seconds.
Answer:
The answer is below
Step-by-step explanation:
Given that mean (μ) of 32.9 seconds and a standard deviation (σ) of 6.4 seconds.
The z score is used to measure by how many standard deviation the raw score is above or below the mean. It is given by:
[tex]z=\frac{x-\mu}{\sigma}\\[/tex]
a) For x < 33.2 seconds
[tex]z=\frac{x-\mu}{\sigma}\\\\z=\frac{33.2-32.9}{6.4} =0.05[/tex]
From the normal distribution table, the probability that a randomly chosen student completes the activity in less than 33.2 seconds = P(x < 33.2) = P(z < 0.05) = 0.5199 = 51.99%
b) For x > 46.6 seconds
[tex]z=\frac{x-\mu}{\sigma}\\\\z=\frac{46.6-32.9}{6.4} =2.14[/tex]
From the normal distribution table, the probability that a randomly chosen student completes the activity in more than 46.6 seconds = P(x > 46.6) = P(z > 2.14) = 1 - P(z < 2.14) = 1 - 0.9927 = 0.0073 = 0.73%
c) For x = 35.5 seconds
[tex]z=\frac{x-\mu}{\sigma}\\\\z=\frac{35.5-32.9}{6.4} =0.41[/tex]
For x = 42.8 seconds
[tex]z=\frac{x-\mu}{\sigma}\\\\z=\frac{42.8-32.9}{6.4} =1.55[/tex]
From the normal distribution table, the proportion of students take between 35.5 and 42.8 seconds to complete the activity = P(35.5 < x < 42.8) = P(0.41< z< 1.55) = P(z < 1.55) - P(z < 0.41) = 0.9332 - 0.6591 = 0.2741 = 27.41%
d) A probability of 75% = 0.75 corresponds to a z score of 0.68
[tex]z=\frac{x-\mu}{\sigma}\\\\0.68=\frac{x-32.9}{6.4} \\\\x-32.9=4.4\\x=4.4+32.9\\x=37.3[/tex]
75% of all students finish the activity in less than 37.3 seconds