This would become 3(7) because of x = 7 in the original equation of 3x and the answer would be 21.
Answer:
3(7)= 21
Step-by-step explanation:
3 x
This means you are multiplying.
x = 7
3(7)= 21
Suppose that 100,000 men were screened for prostate cancer for the first time. Of these, 4,000 men had a positive result on the screening blood test; of those who tested positive, 800 had a biopsy indicating a diagnosis of prostate cancer. Among the remaining 96,000 men who screened negative, 100 developed prostate cancer within the following year and were assumed to be false negatives to the screen. a) set-up the two-by-two table for this data. (please provide an actual table) b) what is the prevalence of prostate cancer in this population? c) calculate and interpret the sensitivity of this screening test d) calculate and interpret the specificity of this screening test. e) Calculate and interpret the positive predictive value of this screening test.
An actual two-by-two table is a tabular representation containing two rows and two columns.
The columns consist of the tested True positive for prostate cancer and tested True Negative for prostate cancerThe rows consist of the predicted positive screening and predicted negative values a)Mathematically, the set-up of the two-by-two table for this data can be computed as:
Tested True Positive for cancer True Negative Total
Predicted Positive 800 3200 4000
Predicted Negative 100 95900 96000
Total 900 99100 100000
b)The prevalence rate of prostate cancer in this population is:
[tex]\mathbf{ =\dfrac{900}{100000}}[/tex]
[tex]\mathbf{ =\dfrac{9}{1000}}[/tex]
= 9 per thousand.
c)
The calculation of the sensitivity of this screening is as follows:
[tex]\mathbf{=\dfrac{TP}{TP+PN_1}}[/tex]
where;
TP = True positive for cancerPN₁ = Predicted Negative for true positive cancer∴
[tex]\mathbf{=\dfrac{800}{800+100}}[/tex]
= 0.889
= 88.9%
The interpretation shows that 88.9% are correctly identified to be actual positive for prostate cancer.
d)The calculation of the specificity of this screening is as follows:
[tex]\mathbf{=\dfrac{PN_2}{PN_2+TN}}[/tex]
where;
TN = True positive for cancerPN₂ = Predicted Negative for true negative cancer∴
[tex]\mathbf{=\dfrac{95900}{95900+3200}}[/tex]
= 0.9677
= 96.77%
The interpretation shows that 96.7% of an actual negative is correctly identified as such.
e)
The positive predicted value of the screening test is computed as:
[tex]\mathbf{= \dfrac{TP}{TP + TN}}[/tex]
[tex]\mathbf{= \dfrac{800}{800 + 3200}}[/tex]
= 0.2
= 20%
The interpretation of the positive predicted value of this screening shows that 20% that are subjected to the diagnosis of positive prostate cancer truly have the disease.
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When Abrams born his parent put $2000 in account that you did 1.2% interest compounded semi annually when he turns 16 in Spain to give him the money to buy a car how much will Abrams you receive on his 16th birthday
Answer:
$2421.95
Step-by-step explanation:
To calculate the final value from compound interest, we can use the formula
A = P(1+r/n)^(nt), where A represents the final amount, P is the initial amount, r is the rate, n is the number of times compounded per time period, and t is the amount of time.
Here, P is 2000, 1.2% is the rate (to convert to a decimal, we can divide by 100 to get 0.012), n = 2 because it is compounded semi-annually, and 16 is the number of years, or t. Plugging these in, we get
2000(1+0.012/2)^(2*16) = 2421.95
House of Mohammed sells packaged lunches, where their finance department has established a
weekly relationship between its Revenue R, in dollars and the number of lunches x, as R=x(82−x)
(a) Write the revenue R, in the form R=ax2+bx+c (b) What is the revenue when 35 lunches are sold? (c) Explain why the graph of R has a maximum.
(d) Write R in the form a(x−h)2+k
(e) How many lunches must be sold for them to achieve their maximum revenue?
(f) State the company's maximum revenue.
(2 marks) (2 marks) (2 marks)
(5 marks)
(2 marks) (2 marks)
(g) Complete the following table of values and graph the Revenue equation using the ordered pairs
(x , R). Label the coordinates of the vertex.
x
10
20
30
40
50
60
70
80
90
R
( 10 marks)
The revenue function is a quadratic equation and the graph of the function
has the shape of a parabola that is concave downwards.
The correct responses are;
(a) R = -x² + 82·x(b) $1,645(c) The graph of R has a maximum because the leading coefficient of the quadratic function for R is negative.(d) R = -1·(x - 41)² + 1,681(e) 41(f) $1,681Reasons:
The given function that gives the weekly revenue is; R = x·(82 - x)
Where;
R = The revenue in dollars
x = The number of lunches
(a) The revenue can be written in the form R = a·x² + b·x + c by expansion of the given function as follows;
R = x·(82 - x) = 82·x - x²
Which gives;
R = -x² + 82·xWhere, the constant term, c = 0
(b) When 35 launches are sold, we have;
x = 35
Which by plugging in the value of x = 35, gives;
R = 35 × (82 - 35) = 1,645
The revenue when 35 lunches are sold, R = $1,645
(c) The given function for R is R = x·(82 - x) = -x² + 82·x
Given that the leading coefficient is negative, the shape of graph of the
function R is concave downward, and therefore, the graph has only a
maximum point.
(d) The form a·(x - h)² + k is the vertex form of quadratic equation, where;
(h, k) = The vertex of the equation
a = The leading coefficient
The function, R = x·(82 - x), can be expressed in the form a·(x - h)² + k, as follows;
R = x·(82 - x) = -x² + 82·x
At the vertex, of the equation; f(x) = a·x² + b·x + c, we have;
[tex]\displaystyle x = \mathbf{-\frac{b}{2 \cdot a}}[/tex]
Therefore, for the revenue function, the x-value of the vertex, is; [tex]\displaystyle x = -\frac{82}{2 \times (-1)} = \mathbf{41}[/tex]
The revenue at the vertex is; [tex]R_{max}[/tex] = 41×(82 - 41) = 1,681
Which gives;
(h, k) = (41, 1,681)
a = -1 (The coefficient of x² in -x² + 82·x)
The revenue equation in the form, a·(x - h)² + k is; R = -1·(x - 41)² + 1,681(e) The number of lunches that must be sold to achieve the maximum revenue is given by the x-value at the vertex, which is; x = 41
Therefore;
The number of lunches that must be sold for the maximum revenue to be achieved is 41 lunches(f) The maximum revenue is given by the revenue at the vertex point where x = 41, which is; R = $1,681
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what is 2 3/15 roumded to the nearest half
Answer:
It is 7 whole
Step-by-step explanation:
3/15 is 5 without anything left plus the 3 is 7
Help me please i really need it
=======================================================
Explanation:
The ratio we want is in the format green:red:total which means we list the number of green first, then the number of red next, then the number total last. The order is very important. This is because we'll simply list the numbers without saying the color name or "total". So the reader will imply what the numbers refer to, based on this order mentioned.
We have:
50 red70 green42 yellow50+70+42 = 120+42 = 162 totalThe ratio of green to red to total is 70:50:162
To reduce the ratio, we divide all three parts of that ratio by the GCF 2
70/2 = 3550/2 = 25162/2 = 81The ratio 70:50:162 fully reduces to 35:25:81 which is the final answer.
This says that for every 35 green marbles, we have 25 red marbles and 81 total marbles.
261,256,251,...
Find the 50th term.
Find the 50th term.
Answer:
16
Step-by-step explanation:
261 - 256 - 251
-5 by step
to 50th term there is 49 -5's from 261.
261 + 49.(-5) = 261 - 245 = 16
Answer:
16
Step-by-step explanation:
The sequence appears to be an arithmetic sequence. To find the 50th term we should create a general formula for the sequence.
General formula of an arithmetic sequence: [tex]a_n=a_1+(n-1)d[/tex]
where An = nth term, a1 = first term , n = number of terms and d = common difference.
The first term is 261 so a1 = 261
The common difference appears to be -5
( 256 - 261 = -5 ) and ( 251 - 256 = -5 )
so d = -5
We want to find the 50th term so n = 50
We then plug all of this in to get the 50th terms
Formula : [tex]a_n=a_1+(n-1)d[/tex]
a1 = 261 , n = 50 and d = -5
[tex]a_n=261 + (50-1)-5[/tex]
subtract 1 from 50
[tex]a_n=261+(49)(-5)[/tex]
multiply 49 and -5
[tex]a_n=261-245[/tex]
subtract 245 from 261
[tex]a_n=16[/tex]
The 50th term is 16
A dolphin dives down into the ocean and resurfaces along a path that is modeled by x^2- 8x + 4y = 0, where the distances are in feet. How many feet is the dolphin from its starting point along the
water's surface?
8 feet
6 feet
4 feet
O feet
please guys i need help
Answer:
6ft
Step-by-step explanation:
The Dolphin is 8 feet apart from starting point along the water surface.
What is Equation?Equations are mathematical statements with two algebraic expressions flanking the equals (=) sign on either side.
It demonstrates the equality of the relationship between the expressions printed on the left and right sides. LHS = RHS is a common mathematical formula.
Coefficients, variables, operators, constants, terms, expressions, and the equal to sign are some of the components of an equation. The "=" sign and terms on both sides must always be present when writing an equation.
Given:
Equation: x²- 8x + 4y = 0
Now, solving for variable 'y' we get
y= (8x - x²) /4
y= 2x - x²/4
So, the Dolphin is 8 feet apart from starting point along the water surface.
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a forrest covers an area of 2400 km^2. if each year the area decreases by 8.5%, what will the area be after 14 years? round answer to nearest square kilometer. (please explain how you get the answer so i can do future questions myself! thank you :) )
Answer:
1581.62810745 square km
Step-by-step explanation:
P = Initial Area = 2500 square km.
r = rate of decreasing = 8.75%
n = number of years = 5 years
A = 2500 ( 1 - 8.75/100)^5
A = 2500 {(100–8.75)/100}^5
A = 2500 (91.25/100)^5
A = 2500 (0.9125)^5
A = 2500 * 0.63265124298
A = 1581.62810745
Let f(x)=5(3)x−4. Evaluate f(6).
Given that:
f(x) = 5(3)x-4
f(6) = 5(3)(6) - 4 ⇛15(6) - 4 ⇛90-4 ⇛86Ans.
7(2e-1)-3=6+6e pls help and do step by step
Answer:
e = 2
Step-by-step explanation:
7(2e - 1) - 3 = 6 + 6e
14e - 7 - 3 = 6 + 6e
14e - 10 = 6 + 6e
14e - 6e - 10 = 6
8e - 10 = 6
8e = 6 + 10
8e = 16
8e/8 = 16/8
e = 2
Recheck:
7(2e - 1) - 3 = 6 + 6e
7(2(2) - 1) - 3 = 6 + 6(2)
7(4 - 1) - 3 = 6 + 12
7(3) - 3 = 18
21 - 3 = 18
18 = 18 ✅
Sam has 60 toy cars. 20% of the cars are red.
How many cars are red?
A. 12
B. 20
C. 48
D. 40
Answer:
A
Step-by-step explanation:
20% of 60 is 12
Hope that helps
A total of $4000 is invested: part at 10% and the remainder at 15%. How much is invested at each rate if the annual interest is $430?
3,400 at 10%
600 at 15%
This is the answer.
state whether each of the following equations represent growth or decay.
Answer:
answer below
Step-by-step explanation:
f(x) = a* bˣ
if a>0 and b>1 : growth
if a>0 and 0<b<1 : decay
5) 7) 9) : growth
6) 8) 10) : decay
When analyzing whether an equation represents growth or decay, we examine the relationship between the variables involved. If an equation shows a positive relationship, it represents growth, while a negative relationship indicates decay.
When determining whether an equation represents growth or decay, we need to examine the relationship between the variables involved. 1. If the equation represents a positive relationship, where as one variable increases, the other variable also increases, then it represents growth. 2. On the other hand, if the equation represents a negative relationship, where as one variable increases, the other variable decreases, then it represents decay.
Let's look at some examples to illustrate this: Example 1: y = 2x In this equation, as x increases, y also increases. Therefore, it represents growth. Example 2: y = -3x In this equation, as x increases, y decreases. Therefore, it represents decay. Example 3: y = -0.5x + 3 Here, as x increases, y decreases. So, this equation represents decay. Example 4: y = 4.5x + 2 As x increases, y also increases. Hence, this equation represents growth. In summary, when analyzing whether an equation represents growth or decay, we examine the relationship between the variables involved. If an equation shows a positive relationship, it represents growth, while a negative relationship indicates decay.
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A group of 8 people are sharing gummy bears each person wants 5 gummy bears each bag has 9 gummy bears
At least 5 bags of gummy bear bags are needed for each person to get 5 gummy bears.
The given parameters;
total number of people sharing the gummy bears, n = 8 peoplenumber of gummy bears in each bag, = 9 gummy bearsnumber of gummy bears needed by each person = 5 gummy bearsThe number of gummy bear bags needed to share 5 gummy bears to each person is calculated as follows;
let the number of gummy bears bag = x
[tex]\frac{9x}{8} = 5\\\\9x = 40\\\\x = \frac{40}{9} \\\\x = 4.4[/tex]
Thus, at least 5 bags of gummy bear bags are needed for each person to get 5 gummy bears.
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Which expression is equivalent to 6(7x - 9)?
Answer:
42x - 54 I think
Step-by-step explanation:
Just simplify it
danny is offering 36$ for 4 hours of swimming lessons. Martin in offering 54$ for 3 hours of swimming lessons. whose offer is better
Answer:
Danny's offer is cheaper
Step-by-step explanation:
Danny is offering 36$ for 4 hours meaning you would do 36÷4=9 (9$ per hour)
Martin is offering 54$ for 3 hours so 54÷3=18 (18$ per hour)
Or the faster way of finding why is Danny is offering more hours for cheaper
Hope this helps
Pls help I’ll brainlest ASAP
A student has a savings account with $475 in it.
She deposits $125 of her paycheck into the account
every week. Her goal is to save $7,000 for college.
How long will it be before she has $1350?
Answer: 7 weeks
Step-by-step explanation:
Let x represent number of weeks
Let y represent the total amount
Amount = Paycheck deposited * number of weeks + Initial amount
y = 125x + 475
Number of weeks until she has $1350
1350 = 125x + 475
125x+475-475=1350-475
125x=875
x=7
Therefore, the student will have $1350 in her bank account after 7 weeks
Line y=2x+3 is tangent to a circle with center (2,-3). Which of the length of the radius of the circle?
Answer:
[tex]2\sqrt{5}[/tex]
Step-by-step explanation:
Since it is tangent to the center, the perpendicular line passes through the center, (2,-3). We find the slope of the perpendicular line to be -1/2 (perpendicular to a slope of 2). We can use point slope form to find the line from the tangent line to the center:
y+3=-1/2(x-2)
We can simplify this to
y= -1/2x-2
We can then check the point of intersection:
-1/2x-2=2x+3
-5=2.5x
x=-2
we can plug this in to the first equation to get y=2(-2)+3=-1
So the point of intersection of the circle and the tangent line is (-2,-1)
Then we find the distance of this point to (2,-3) and we can use pythagorean theorem.
[tex]\sqrt{(-2-2)^{2}+(-1-(-3))^{2} } =\sqrt{(-4)^{2}+2^{2} } =\sqrt{20} =2\sqrt{5}[/tex]
The radius of the circle is [tex]2\sqrt{5}[/tex]
For Line y=2x+3 is tangent to a circle with center (2,-3) then the length of the radius of the circle is 10/√5
What is Distance?The length along a line or line segment between two points on the line or line segment.
Distance=√(x₂-x₁)²+(y₂-y₁)²
The line y=2x+3 is tangent to the circle with center (2,-3)
The distance from the center of the circle to the line is equal to the radius of the circle.
The distance from a point (x₁, y₁) to a line Ax + By + C = 0 is given by the formula:
d = |Ax₁+ By₁ + C| /√A² + B²
The equation of the line is y = 2x + 3, which can be written in the form Ax + By + C = 0 as (-2)x + y - 3 = 0.
d = |-2(2) + (-3) - 3| / √(-2)² + 1²
d=10/√5
The radius of the circle is equal to the distance from the center to the tangent line, which is:
radius = 10/√5
Hence, for Line y=2x+3 is tangent to a circle with center (2,-3) then the length of the radius of the circle is 10/√5
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Type the correct answer in each box.
Quadrilateral EBCD is an isosceles trapezoid with m∠EDC = 110°, m∠ABC = 133°, and m∠DEA = 114°.
m∠DEB = __°
m∠BCD= __°
m∠EAB= __°
Answer:
m∠DEB = _70_°
m∠BCD= _110_°
m∠EAB= _73_°
Step-by-step explanation:
To find ∠DEB:
Take the angle of ∠EDC, which is 110°. We know the total degree in a triangle is 180°. So, we do 180° - 110° to get 70°.
To find ∠BCD:
Because EBCD is an isosceles trapezoid, this means that ∠D and ∠C both have the congruent angles. Since we know ∠EDC is 110°, this means that ∠C is also 110°.
To find ∠EAB:
We know that m∠ABC is 133° and ∠DEA is 114°. However, both angles count both the triangle and trapezoid. Previously we figured out that ∠DEB is 70°. We'll take the angle of ∠DEA and subtract the angle of ∠DEB from it, which gets us 44°. To figure out the angle of ∠B, we take the angle of ∠ABC and subtract 70° or the angle of ∠DEB, which gets us 63°. Now we take the total degree of a triangle, 180° and minus both 44° and 63° from it, which is 73°.
- 2021 Edmentum
Ray had $50. he bought two shirts that cost $19 each. how much money did Ray have after buying the shirts? Alex's answer to the word problem is $29. Is Alex's answer reasonable? explain.
no why? cause the guy bought 2 shirts for 19 dollors each where was he at nikes? on average a shirt cost 15 bucks but 19? yeah no
Answer:
Step-by-step explanation:
no why? cause the guy bought 2 shirts for 19 dollors each where was he at nikes? on average a shirt cost 15 bucks but 19? yeah no
Find the volume in cubic feet of a rectangular moving van with length 14 feet, width 7 feet, and height 7 feet
Answer:
length (l) = 14 feet
breadth (b) = 7 feet
height (h) = 7 feet
so, volume of the
rectangular moving
van = l*b*h
=14feet * 7feet *7feet
= 686 cubic feet
The candy store is selling Twizzlers. They have a sale of four Twizzlers for $6.00. Which equation below represents this proportional relationship?
A. y=1.5x C. y= x 2/3 B. x= 4y D. x= 6y
Answer:A. y=1.5x
Step-by-step explanation:
x represents the number of twizzlers
1.5 represents the the price that you have to pay for each Twizzlers
And y represents the total cost
Find the perimeter of the rectangle whose: length = 1m, breadth = 75cm
Pls all answer fast PLS
Answer:
The perimeter of the rectangle is 3.5 m or 350 cm.
Hope you could get an idea from here.
Doubt clarification - use comment section.
pls help wiht this question ill give you 69 points whoever awnsers
Answer:
what's thequestion?
Step-by-step explanation:
An online survey asked a sample of high school students their favorite type of music, and the results were tabulated above. Find the probability that a person chosen at random did not choose pop music, given that the student is a sophomore or a junior.
Answer:
87/103
Step-by-step explanation:
Find the values of the variables.
Answer:
x = 50
y = 65
Step-by-step explanation:
The marked sides show you that the triangle is isosceles. That means the base angles, y° and 65°, are congruent.
y = 65
__
The sum of the angles in a triangle is 180°.
65° +65° +x° = 180°
x° = 180° -130° = 50° . . . . . . subtract 130°
x = 50
If y= cos x, what x-value corresponds to a y-value of 1/2 between pi and 2 pi
Answer:
pi/3, 5pi/3
Step-by-step explanation:
We can see that when cosine is at 1/2, the angle measures are pi/3 degrees and 5pi/3 degrees. You can use a unit circle to find this. You can also find arccos(1/2), but that will only give you the value pi/3, not 5pi/3.
We can plug these in to find that they are indeed equal to 1/2.
The x-value that corresponds to a y-value of 1/2 between π and 2π is π/3.
Here, we have,
To find the x-value that corresponds to a y-value of 1/2 between π and 2π for the equation y = cos(x), we can use the inverse cosine function (also known as arccosine or cos⁻¹).
The inverse cosine function will give us the angle whose cosine is a specific value.
In this case, we want to find the angle whose cosine is 1/2.
Using the inverse cosine function, we can write the equation as:
x = arccos(1/2)
To solve this equation, we need to evaluate the inverse cosine of 1/2. In general, the inverse cosine of a value returns an angle between 0 and π (180 degrees). In this case, we are interested in finding an angle between π and 2π.
The value of arccos(1/2) is π/3.
Therefore, the x-value that corresponds to a y-value of 1/2 between π and 2π is π/3.
It's important to mention that the cosine function is periodic, so there are multiple x-values that can correspond to a y-value of 1/2. In this case, we have chosen the x-value that lies between π and 2π.
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I need help with this