Answer:
b. 2/15
c. 7/15
Step-by-step explanation:
total frequency = 45
X 0 1 2 3 4 5 6 7
P(x) 1/45 7/45 2/45 1/15 4/45 1/9 2/15 7/45
b. P(≥4) = 18/45 = 2/5
c. P(<3) = 21/45 = 7/15
A grading scale is set up for 1000 students' test scores. It assumes the
scores are normally distributed with a mean score of 75 and a standard
deviation of 15.
How many students will score between 48 and 75?
hint: recall how to get the standard deviation. What does that mean in
this context? How could you use that to understand how many test
scores could be in one standard deviation?
464
Answer:
464 students will score between 48 and 75. Using the z-distribution, we measure how many standard deviations each score is from the mean, then find the p-value associated with each score to find the proportion, and from the proportion, we find how many out of 1000.
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
It assumes the scores are normally distributed with a mean score of 75 and a standard deviation of 15.
This means that [tex]\mu = 75, \sigma = 15[/tex]
How many students will score between 48 and 75?
First we find the proportion, which is the pvalue of Z when X = 75 subtracted by the pvalue of Z when X = 48. So
X = 75
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{75 - 75}{15}[/tex]
[tex]Z = 0[/tex]
[tex]Z = 0[/tex] has a p-value of 0.5
X = 48
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{48 - 75}{15}[/tex]
[tex]Z = -1.8[/tex]
[tex]Z = -1.8[/tex] has a p-value of 0.0359
1 - 0.0359 = 0.4641
Out of 1000:
0.4641*1000 = 464
464 students will score between 48 and 75. Using the z-distribution, we measure how many standard deviations each score is from the mean, then find the p-value associated with each score to find the proportion, and from the proportion, we find how many out of 1000.
I need help ☹️ anybody know if it’s a b c or d
Answer:
C
Step-by-step explanation:
There are 60 teachers in the school. 40 of them are from Ireland. What fraction of teachers are from Ireland?
HELP PLEASEEEEEEEEEEEEEEE
Answer:
Step-by-step explanation:
12²+15² is 369. square root of 369 is 3[tex]\s\sqrt{41[/tex] or 19.2
What is the mean of the data set?
25, 18, 16, 25
Answer:
21
Step-by-step explanation:
Add all of the numbers and then divide by how many numbers there are.
In ancient Egypt, mathematicians and architects used 10 as an approximation for π . The circular floor of an ancient arena is paved with tiles. The floor of the arena has a radius of 100 feet.
The radius of a circle is 8 cm. Find the circumference of the circle. Use 3.14
for Pi.
Answer:
50.24 cm
Step-by-step explanation:
For the easier computation of a circle's circumference, pi's value is taken to be 3.14 (π = 3.14). Let's see a few examples below to polish the concept of the circumference. Find the circumference of the circle with a radius of 8 cm. = 50.24 cm.
Answer:
Hello! answer: 50.24
Step-by-step explanation:
To find circumference you just have to do diameter × pi Since we arent given the diameter we have to figure it out BUT REMEMEBER diameter is just twice the radius so 8 × 2 = 16 so 16 is our diameter! Now we just multiply that by pi so 16 × 3.14 = 50.24 So 50.24 is the circumference! Hope this helps!
Hey Some One Help With This Please
NO LINKS PLEASEEEEEE!
HELP!!
Answer:
option d will match friend
Whats 9 + 10 = ??
If ykyk :P
Answer:
19 is answer kxkdndnskaskznzb
Answer:
9 + 10 = 19
Step-by-step explanation:
... ... ... ... ...
No links please need help
the circumference of an ellipse is approximated by…
9514 1404 393
Answer:
see attached
Step-by-step explanation:
To solve for b, undo what is done to b.
[tex]\displaystyle C=2\pi\sqrt{\frac{a^2+b^2}{2}}\\\\\frac{C}{2\pi}=\sqrt{\frac{a^2+b^2}{2}}\\\\\left(\frac{C}{2\pi}\right)^2=\frac{a^2+b^2}{2}\\\\\frac{C^2}{2\pi^2}=a^2+b^2\\\\\frac{C^2}{2\pi^2}-a^2=b^2\\\\\boxed{b=\sqrt{\frac{C^2}{2\pi^2}-a^2}}[/tex]
FREE POINT GIVE AWAY!!!!!! Just solve my equation 5*4+2=? (I already know the answer)
Answer:
22
Step-by-step explanation:
I did the math in my head sooo if it's wrong I know why
Answer:
19
Step-by-step explanation:
I put it in my calculator
Answer:
D. 19
hope this helps
have a good day :)
Step-by-step explanation:
Help me please! It’s math rewrite each expression as a single power. Whoever helps gets brainly and gives stars and does it right please.
Answer:
1. [tex]6^{8}[/tex]
2. [tex]5^{10}[/tex]
3. [tex]2^{9-5}[/tex]
4. [tex]3^{6}[/tex]
5. [tex]12^8[/tex]
6. [tex](7^2)^2[/tex]
Step-by-step explanation:
have a good day! :)
What value of y will make lines j, k, and l parallel?
Answer: picture isn't clear
Step-by-step explanation:
What is the degree of the equation?
What is the Leading Coefficient of the equation ?
Solve using the Quadratic Equation.
5X^2 – 3X – 8=0
Answer:
1 (give brainliest plss)
Step-by-step explanation:
Step-1 : Multiply the coefficient of the first term by the constant 5 • -8 = -40
Step-2 : Find two factors of -40 whose sum equals the coefficient of the middle term, which is -3 .
-40 + 1 = -39
-20 + 2 = -18
-10 + 4 = -6
-8 + 5 = -3 That's it
Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, -8 and 5
5x2 - 8x + 5x - 8
Step-4 : Add up the first 2 terms, pulling out like factors :
x • (5x-8)
Add up the last 2 terms, pulling out common factors :
1 • (5x-8)
Step-5 : Add up the four terms of step 4 :
(x+1) • (5x-8)
Which is the desired factorization
[tex]\mathfrak{\huge{\orange{\underline{\underline{AnSwEr:-}}}}}[/tex]
Actually Welcome to the concept of Quadratic Equations.
Degree of a equation represents the highest power of the varible in the equation, For quadratic equation the degree is 2.
Leading Coefficient are the constant numbers that are significantly multiplied with the variables in the equation.
==> 5x^2 - 3x - 8 = 0
==> 5x^2 -8x +5x -8=0
==> x(5x-8) +1(5x-8)=0
==> (5x-8)(x+1) = 0
Koto traveled 5,000 meters north from her house with an average velocity of 4.5 m/s. What was the time of her trip? (There are 60 seconds in 1 minute.)
Answer:
18.5
Step-by-step explanation:
took the test on edg.
Answer:
18.5 minutes
Step-by-step explanation:
divide 5000 m/ 4.5 m/s = 1,111 seconds
1,111/60= 18.5 min
Please help marking people as brainlist
100% = Ex Which expression is the same as multiply 3 and 2, add 5 to the product, then multiply by 10? A. (3 x 2) + 5 x 10 B. (3 x 2 x 10) + 5 O c. 3x (2 + 5) x 10 O D. (3 x 2 + 5) x 10
Answer:
this is the answer
A. (3 x 2) + 5 x 10
Enter the absolute value of 6.2 and -7/2
Answer:
1, 6.2 and 7/2
Step-by-step explanation:
Answer:
6.2 = 6.2
-7/2= 3.5
Step-by-step explanation:
Because I know, mark brainliest please
help me please I dont know this
Answer:
answer: 384
Step-by-step explanation:
Hello! cubes are very simple! since there all the same measure and 6 faces all we have to do is 8 × 8 = 64 sense we know 1 face is 64 we just have to multiply by 6 cause there is 6 faces so
64 × 6 = 384 Hope this helps you!
tbh chick-fil-a is overrated
Answer:
no chick fil a is not but kinda is
Answer:
I love Chick-fil a
Step-by-step explanation:
2.52343454 + -34355343.99
NEED HELP PLZZZZZZ ASAP
Answer:
5555555555555555555555555555555555555 trust
Step-by-step explanation:
Identify the constant term of
14 - 8x - 7y
Answer:
14
Step-by-step explanation:
Two points are 17 units apart on a number line. The coordinate of one point is -20.
What are the possible coordinates of the other?
A. -3 and +3
B. -37 and +3
C. -37 and -3
D. +37 and +3
E. +37 and -3
need help asappppppp
Answer:
for what
Step-by-step explanation:
Can someone show me how to do this? You have to find the side length or angle measure.
Answer: Add the other two lengths together. 18plus21
Step-by-step explanation:
please answer ive been waiting half hour
Every plant bloomed in the spring. The simple subject of this sentence is _____.
every
every plant
plant
bloomed
The subject is the idea,being or thing being discussed.
Should be "plant". Its the Main thing being discussed.
A disc has a diameter of 23 cm the inner hole in the disc has a radius of 2 cm find the circumference for both the inner hole and the entire disc round to the nearest whole centimeter
Answer:
The diameter of the entire disc is 72.22 cm, that is, 72 cm rounded to the nearest whole centimeter. In turn, the diameter of the inner circle is 12.56 cm, that is, 13 cm rounded to the nearest whole centimeter.
Step-by-step explanation:
Given that a disc has a diameter of 23 cm and the inner hole in the disc has a radius of 2 cm, to find the circumference for both the inner hole and the entire disc the following calculations must be performed, knowing that the circumference of a Circle is calculated by multiplying 3.14 by the diameter, which in turn measures twice the radius:
23 x 3.14 = X
72.22 = X
Therefore, the diameter of the entire disc is 72.22 cm, that is, 72 cm rounded to the nearest whole centimeter.
3.14 x (2 x 2) = X
3.14 x 4 = X
12.56 = X
In turn, the diameter of the inner circle is 12.56 cm, that is, 13 cm rounded to the nearest whole centimeter.
The local branch of the Internal Revenue Service spent an average of 21 minutes helping each of 10 people prepare their tax returns. The standard deviation was 5.6 minutes. A volunteer tax preparer spent an average of 27 minutes helping 14 people prepare their taxes. The standard deviation was 4.3 minutes. At α = 0.02, is there a difference in the average time spent by the two services? Find the 98% confidence interval for the two means.
a. State the hypotheses and identify the claim.
b. Find the critical value(s).
c. Compute the test value.
d. Make the decision.
Answer:
The confidence Interval is [- 0.7053 10.4521]
a: The hypotheses are
H0: μ1=μ2 against the claim Ha :μ1≠μ2
b. The critical value for t∝/2 for 17 d.f t > 2.508 and t < -2.111
c. t= -2.8422
d. The calculated value of t= -2.8422 is less than t < -2.11 the critical value therefore we reject H0 and conclude there is a difference between the two means.
Step-by-step explanation:
When the standard deviations are not the same then the confidence intervals for mean differences are calculated as
(x1`-x2`)- t∝/2 √s1²/n1 + s2²/n2 < u1-u2 < (x1`-x2`)+ t∝/2 √s1²/n1 + s2²/n2
x1`= 21 x2`= 27
n1= 10 n2= 14
s1= 5.6 s2= 4.3
The degrees of freedom is calculated using
υ = [s₁²/n1 + s₂²/n2]²/ (s₁²/n1 )²/ n1-1 + (s₂²/n2)²/n2-1
= 17
The t∝/2 for 17 d.f = 2.11
Putting the values
(x1`-x2`)- t∝/2 √s1²/n1 + s2²/n2 < u1-u2 < (x1`-x2`)+ t∝/2 √s1²/n1 + s2²/n2
(21-27) - 2.11√5.6²/10+ 4.3²/14 < u1-u2 <(21-27) +2.11√5.6²/10+4.3²/14
6- 2.11*2.111 < u1-u2 < ( 6 ) +2.11*2.111
6- 4.4521 < u1-u2 < ( 6 ) +5.294
- 1.5479 < u1-u2 < 10.4521
The confidence Interval is [- 0.7053 10.4521]
a: The hypotheses are
H0: μ1=μ2 against the claim Ha :μ1≠μ2
The claim is that there is a difference in the average time spent by the two services
b. The critical value for t∝/2 for 17 d.f t > 2.508 and t < -2.111
The degrees of freedom is calculated using
υ = [s₁²/n1 + s₂²/n2]²/ (s₁²/n1 )²/ n1-1 + (s₂²/n2)²/n2-1
= 17
c. The test statistic is
t= (x1`-x2`) /√s1²/n1 + s2²/n2
t= (21-27) /√5.6²/10+ 4.3²/14
t= -6/2.111
t= -2.8422
d. The calculated value of t= -2.8422 is less than t < -2.11 the critical value therefore we reject H0 and conclude there is a difference between the two means.