A psychology professor assigns letter grades on a test according to the following scheme. A: Top 14% of scores B: Scores below the top 14% and above the bottom 65% C: Scores below the top 35% and above the bottom 16% D: Scores below the top 84% and above the bottom 9% F: Bottom 9% of scores Scores on the test are normally distributed with a mean of 68.4 and a standard deviation of 9.7. Find the numerical limits for a B grade. Round your answers to the nearest whole number, if necessary.

Answers

Answer 1

Answer:

The numerical limits for a B grade are 72 and 79, that is, a score between 72 and 79 results in a B grade.

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.

Scores on the test are normally distributed with a mean of 68.4 and a standard deviation of 9.7.

This means that [tex]\mu = 68.4, \sigma = 9.7[/tex]

Find the numerical limits for a B grade.

Below the 100 - 14 = 86th percentile and above the 65th percentile.

65th percentile:

X when Z has a p-value of 0.65, so X when Z = 0.385.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]0.385 = \frac{X - 68.4}{9.7}[/tex]

[tex]X - 68.4 = 0.385*9.7[/tex]

[tex]X = 72[/tex]

86th percentile:

X when Z has a p-value of 0.86, so X when Z = 1.08.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]1.08 = \frac{X - 68.4}{9.7}[/tex]

[tex]X - 68.4 = 1.08*9.7[/tex]

[tex]X = 79[/tex]

The numerical limits for a B grade are 72 and 79, that is, a score between 72 and 79 results in a B grade.


Related Questions

Please help on this initial amount problem

Answers

Initial amount: 27,500
Growth
Value of car change 28% each year

Divide 5x^2+3x-2 by x + 1

Answers

5x + 8

I used long division

what are the zeros of this function?

Answers

Answer:

the Ans is c

Step-by-step explanation:

actually I don't know how to explain

Fraces bonitas para decirle a tu nv?

minimo 6

Answers

Answer:

it's. is now the MA plz I miss you

si pudiera escoger entre vivir eternamente y vivir dos veces

yo escogeria vivir dos veces porque vivir una vida eterna sin ti a mi lado seria el mayor sufrimiento, ahora vivir dos veces me dejaria tranquilo porque despues del final de mi vida podria volver a encontrarme contigo y vivir todos los momentos bellos una vez mas y eso seria un sueño volviendose realidad

If 800g of a radioactive substance are present initially and 8 years later only 450g remain, how much of the substance will be present after 16 years? (Round answer to a whole number)

Answers

A=Pe^(rt)

P = 800g

t = 8 years

A = 450g

r = This is what we will try and find to start with

450=800e^(r*8)

After running the math through a calculator, we end with r = -0.07192

Now we just re-input this information into our equation: A=800e^(-0.07192*16)

A=800e^(1.15072)

Now we will re-write the equation using the negative exponent rule:

A = 800 1/e^1.15072

Combine right side:

A = 800/e^1.15072

Then do the math:

A = 253.12709836......

That will give us A = 253 (rounded to the whole number)

I hope this helps! :)

The substance that should be presented after 16 years is 253.

Given that,

If 800g of a radioactive substance are present initially and 8 years later only 450g remain.

Based on the above information, the calculation is as follows:

We know that

[tex]A=Pe^{rt}[/tex]

Here

P = 800g

t = 8 years

A = 450g

[tex]450=800e^{r\times 8}\\\\A=800e^{-0.07192\times 16}\\\\A=800e^{1.15072}\\\\A = 800 \ 1 \div e^{1.15072}\\\\A = 800\div e^{1.15072}[/tex]

A = 253

Therefore we can conclude that the substance that should be presented after 16 years is 253.

Learn more: brainly.com/question/16115373

What number can go in the box to make the number sentence true?
6 + 0 = 10
0.
4.
6.
10.

Answers

I believe it would be 4 lil man

Find the missing length indicated

Answers

Answer:

x = 175

Step-by-step explanation:

Building A is 170 feet shorter than building B. The total height of the two building is 1490 feet. Find the height of each building.

Answers

Answer:

Building A is 660 feet and Building B is 830 feet

Step-by-step explanation:

Let x represent the height of building B.

Since building A is 170 feet shorter than building B, it can be represented by x - 170.

Create an equation and solve for x:

(x) + (x - 170) = 1490

2x - 170 = 1490

2x = 1660

x = 830

So, the height of building B is 830 feet.

Subtract 170 from this to find the height of building A:

830 - 170

= 660

Building A is 660 feet and Building B is 830 feet

Help please guys thanks

Answers

Answer:

5

Step-by-step explanation:

(625 ^2)^(1/8)

Rewriting 625 as 5^4

(5^4 ^2)^(1/8)

We know that a^b^c = a^(b*c)

5^(4*2)^1/8

5^8 ^1/8

5^(8*1/8)

5^1

5

Answer:

[tex]5[/tex]

Step-by-step explanation:

[tex] { {(625}^{2} )}^{ \frac{1}{8} } \\ { ({25}^{2 \times 2} )}^{ \frac{1}{8} } \\ {25}^{4 \times \frac{1}{8} } \\ {5}^{2 \times 4 \times \frac{1}{8} } \\ {5}^{ \frac{8}{8} } \\ {5}^{1} \\ = 5[/tex]

cho f(x)= sign x và g(x) = x(1-x^2). tìm f(g(x))

Answers

Answer:

[tex]f(g(x))= sign(x(1-x^{2})) = sign(x-x^{3})[/tex]

Step-by-step explanation:

A rope is 56 in length and must be cut into two pieces. If one piece must be six times as long as the other, find the length of each piece. Round your answers to the nearest inch, if necessary.

Answers

Answer:

48, 6

Step-by-step explanation:

The ratio of the pieces is 6 to 1

Add them together to get the total

6+1 = 7

Divide the total length by 7

56/7 = 8

Multiply the ratios by 8

6*8 = 48

 1*8 = 6

The peices are 48 and 6

Evaluate z^2−3 z+4 , when z=−4

Answers

Answer:

8

Step-by-step explanation:

=z²-3z+4 when z is 4

=4²-3(4)+4

=16-12+4

=8

It should be -19

I got the answer by plugging it into Desmos scientific calculator.

Suppose you make napkin rings by drilling holes with different diameters through two wooden balls (which also have different diameters). You discover that both napkin rings have the same height 5h. Use cylindrical shells to compute the volume V of a napkin ring of height 5 h created by drilling a hole with radius r through the center of a sphere of radius R and express the answer in terms of h .

Answers

Answer:

V = 1/6 π ( 5h)^3

Step-by-step explanation:

Height of napkin rings = 5h

Compute the volume V of a napkin ring

let a = 5

radius = r

express answer in terms of h

attached below is the detailed solution

18. Which of the following is true for a circle that has a circumference of approximately 75 feet?
O The diameter is approximately 12 feet.
O The radius is approximately 12 feet.
O The radius is approximately 12 square feet.
O The diameter is approximately 12 square feet.

Answers

Answer:

A) The diameter is approximately 12 feet.

Step-by-step explanation:

C= piD

sq ft would be wrong bc this is not talking ab area

Which expression is equivalent to 3(x - y) + y? 3x - 4y 3x - 3y 3x - 2y 3(x - 2y)

Answers

9514 1404 393

Answer:

  (c)  3x - 2y

Step-by-step explanation:

Use the distributive property to eliminate parentheses, then collect terms.

  3(x -y) +y = 3x -3y +y = 3x +(-3+1)y = 3x -2y

Now we have to find,

The expression which is equivalent to,

→ 3(x - y) + y

Let's get the solution,

→ 3(x - y) + y

→ 3x - 3y + y

→ 3x - 2y

Hence, required expression is 3x - 2y.

How would yo expand ln (1/49k)?

Answers

Answer:

Step-by-step explanation:

It depends on whether you mean ln(1/49k) or ln(1/(49k)).

When a fridge is imported, a customs value of 10% must be paid for its value. If the value of the fridge after paying the customs value is rs. 55,000/-. What is the value before paying customs duty?

Answers

Answer:

55000×100/90

61,111.111

1. Consider a lottery with three possible outcomes:-$125 will be received with probability 0.2-$100 will be received with probability 0.3-$50 will be received with probability 0.5a. What is the expected value of the lottery

Answers

Answer:

The expected value of the lottery is $80

Step-by-step explanation:

To get the expected value, we have to multiply each outcome by its probability

Then we proceed to add up all of these to get the expected value of the lottery

we have this as ;;

125(0.2) + 100(0.3) + 50(0.5)

= 25 + 30 + 25 = $80

Which of the following displays cannot be used to compare data from two different sets?

Answers

Answer:

Scatter plot charts are good for relationships and distributions, but pie charts should be used only for simple compositions — never for comparisons or distributions.


15. Find the x- and y-intercepts for the lineal equation - 3x + 4y = 24

Please explain steps! ❤️

Answers

Answer:

x (-8,0)

y (0,6)

Step-by-step explanation:

at the x-intercept, y = 0

at the y-intercept x=0

sub those values into your equation!

for the x-intercept,

-3x = 24

x = -8

for the y-intercept,

4y = 24

y = 6

what’s the missing side of the polygons

Answers

Answer:

the missing side is 21!!!!!!!!

i got 21 but i may be wrong :)

find x in this similar triangles

Answers

Answer:

6. x = 4

8. x = 13

Step-by-step explanation:

Using similar triangles theorem,

6. (5+4)/5 = (4x + 2)/(4x + 2 - 8)

9/5 = (4x + 2)/(4x - 6)

Cross multiply

9(4x - 6) = 5(4x + 2)

36x - 54 = 20x + 10

Collect like terms

36x - 20x = 54 + 10

16x = 64

16x/16 = 64/16

x = 4

8. (4x + 13)/20 = 52/16

(4x + 13)/20 = 13/4

Cross multiply

4(4x + 13) = 13(20)

16x + 52 = 260

16x = 260 - 52

16x = 208

x = 208/16

x = 13

PLEASE HELPPPPPPPPPPP

Answers

Answer:

P(S or T) = 3/4

Step-by-step explanation:

Which of the following is a solution to 2sin2x+sinx-1=0?

Answers

Answer:

270 degrees

Step-by-step explanation:

If you plug in 270 in place of the x's, the function is true!

This is correct for Plate/Edmentum users!! Hope I could help :)

what 30 + 30+60+(56)-82=?

Answers

94 is the correct answer for that question

Step-by-step explanation:

30+30+60+56-82=94

Answer theas question

Answers

(1) Both equations in (a) and (b) are separable.

(a)

[tex]\dfrac xy y' = \dfrac{2y^2+1}{x+1} \implies \dfrac{\mathrm dy}{y(2y^2+1)} = \dfrac{\mathrm dx}{x(x+1)}[/tex]

Expand both sides into partial fractions.

[tex]\left(\dfrac1y - \dfrac{2y}{2y^2+1}\right)\,\mathrm dy = \left(\dfrac1x - \dfrac1{x+1}\right)\,\mathrm dx[/tex]

Integrate both sides:

[tex]\ln|y| - \dfrac12 \ln\left(2y^2+1\right) = \ln|x| - \ln|x+1| + C[/tex]

[tex]\ln\left|\dfrac y{\sqrt{2y^2+1}}\right| = \ln\left|\dfrac x{x+1}\right| + C[/tex]

[tex]\dfrac y{\sqrt{2y^2+1}} = \dfrac{Cx}{x+1}[/tex]

[tex]\boxed{\dfrac{y^2}{2y^2+1} = \dfrac{Cx^2}{(x+1)^2}}[/tex]

(You could solve for y explicitly, but that's just more work.)

(b)

[tex]e^{x+y}y' = 3x \implies e^y\,\mathrm dy = 3xe^{-x}\,\mathrm dx[/tex]

Integrate both sides:

[tex]e^y = -3e^{-x}(x+1) + C[/tex]

[tex]\ln(e^y) = \ln\left(C - 3e^{-x}(x+1)\right)[/tex]

[tex]\boxed{y = \ln\left(C - 3e^{-x}(x+1)\right)}[/tex]

(2)

(a)

[tex]y' + \sec(x)y = \cos(x)[/tex]

Multiply both sides by an integrating factor, sec(x) + tan(x) :

[tex](\sec(x)+\tan(x))y' + \sec(x) (\sec(x) + \tan(x)) y = \cos(x) (\sec(x) + \tan(x))[/tex]

[tex](\sec(x)+\tan(x))y' + (\sec^2(x) + \sec(x)\tan(x)) y = 1 + \sin(x)[/tex]

[tex]\bigg((\sec(x)+\tan(x))y\bigg)' = 1 + \sin(x)[/tex]

Integrate both sides and solve for y :

[tex](\sec(x)+\tan(x))y = x - \cos(x) + C[/tex]

[tex]y=\dfrac{x-\cos(x) + C}{\sec(x) + \tan(x)}[/tex]

[tex]\boxed{y=\dfrac{(x+C)\cos(x) - \cos^2(x)}{1+\sin(x)}}[/tex]

(b)

[tex]y' + y = \dfrac{e^x-e^{-x}}2[/tex]

(Note that the right side is also written as sinh(x).)

Multiply both sides by e ˣ :

[tex]e^x y' + e^x y = \dfrac{e^{2x}-1}2[/tex]

[tex]\left(e^xy\right)' = \dfrac{e^{2x}-1}2[/tex]

Integrate both sides and solve for y :

[tex]e^xy = \dfrac{e^{2x}-2x}4 + C[/tex]

[tex]\boxed{y=\dfrac{e^x-2xe^{-x}}4 + Ce^{-x}}[/tex]

(c) I've covered this in an earlier question of yours.

(d)

[tex]y'=\dfrac y{x+y}[/tex]

Multiply through the right side by x/x :

[tex]y' = \dfrac{\dfrac yx}{1+\dfrac yx}[/tex]

Substitute y(x) = x v(x), so that y' = xv' + v, and the DE becomes separable:

[tex]xv' + v = \dfrac{v}{1+v}[/tex]

[tex]xv' = -\dfrac{v^2}{1+v}[/tex]

[tex]\dfrac{1+v}{v^2}\,\mathrm dv = -\dfrac{\mathrm dx}x[/tex]

[tex]-\dfrac1v + \ln|v| = -\ln|x| + C[/tex]

[tex]\ln\left|\dfrac yx\right| -\dfrac xy = C - \ln|x|[/tex]

[tex]\ln|y| - \ln|x|  -\dfrac xy = C - \ln|x|[/tex]

[tex]\boxed{\ln|y| -\dfrac xy = C}[/tex]

Help please!! Based on Pythagorean identities, which equation is true ??

Answers

Answer:

Last answer: [tex]cot^{2} \alpha - csc^{2} \alpha = -1[/tex]

sorry couldn't find theata so I just used alpha.

The following data represents the age of 30 lottery winners.

22 30 30 35 36 37 37
37 39 39 41 51 51 54
54 55 57 57 58 58 61
64 68 69 72 74 75 78 79 80

Complete the frequency distribution for the data.

Age Frequency
20-29
30-39
40-49
50-59
60-69
70-79
80-89

Answers

Door key nhfsssrtgfrtgbkoooo your name and number of your name on the card number for you and the name is your
Ages. ==> Frequencies
20-29 ==> 1
30-39 ==> 9
40-49 ==> 1
50-59 ==> 9
60-69 ==> 4
70-79 ==> 5
80-89 ==> 1
(Total 30)

Rate of change or rate of change

A farmer has 80 feet of wire mesh to surround a rectangular pen.
A) Express the area A of the pen as a function of x, also draw the figure of A indicating the admissible values ​​of x for this problem.
B) What are the dimensions of the maximum area pen?

Answers

Answer:

Step-by-step explanation:

A). Let the dimensions of the rectangular pen are,

Length = l

Width = x

Since, farmer has the wire measuring 80 feet to surround the the pen.

Perimeter of the pen = 80 feet

2(l + x) = 80

l + x = 40

l = 40 - x ------(1)

Area of the rectangular pen = Length × width

                                               = lx

By substituting the value of l from equation (1),

Area (A) of the pen will be modeled by the expression,

A = (40 - x)

A = 40x - x²

B). For maximum area of the pen,

Derivative of the area = 0

[tex]\frac{d}{dx}(A)=0[/tex]

[tex]\frac{d}{dx}(A)=\frac{d}{dx}(40x-x^2)[/tex]

         = 40 - 2x

And (40 - 2x) = 0

x = 20

Therefore, width of the pen = 20 feet

And length of the pen = 40 - 20

                                     = 20 feet

Dimensions of the pen should be 20 feet by 20 feet.

Game consoles: A poll surveyed 341 video gamers, and 95 of them said that they prefer playing games on a console, rather than a computer or hand-held device. An executive at a game console manufacturing company claims that the proportion of gamers who prefer consoles differs from . Does the poll provide convincing evidence that the claim is true

Answers

Answer:

proportion of gamers who prefer console does not differ from 29%

Step-by-step explanation:

Given :

n = 341 ; x = 95 ; Phat = x / n = 95/341 = 0.279

H0 : p = 0.29

H1 : p ≠ 0.29

The test statistic :

T = (phat - p) ÷ √[(p(1 - p)) / n]

T = (0.279 - 0.29) ÷ √[(0.29(1 - 0.29)) / 341]

T = (-0.011) ÷ √[(0.29 * 0.71) / 341]

T = -0.011 ÷ 0.0245725

T = - 0.4476532

Using the Pvalue calculator from test statistic score :

df = 341 - 1 = 340

Pvalue(-0.447, 340) ; two tailed = 0.654

At α = 0.01

Pvalue > α ; We fail to reject the null and conclude that there is no significant evidence that proportion of gamers who prefer console differs from 29%

Other Questions
The given equation has been solved in the table.Step1: x/2-7=-7Step2: x/2-7+7=-7+7Step3: x/2=0Step4: 2x/2=20Step5: x=0.step 2OBstep 3O c.step 4ODThe subtraction property of equality was not applied to solve this equation. A pinion and gear pair is used to transmit a power of 5000 W. The teeth numbers of pinion and gear are 20 and 50. The module is 5 mm, the pressure angle is 20oand the face width is 45 mm. The rotational speed of pinion is 300 rev/min. Both the pinion and the gear material are Nitralloy 135 Grade2 with a hardness of 277 Brinell. The quality standard number Qv is 5 and installation is open gearing quality. Find the AGMA bending and contact stresses and the corresponding factors of safety for a pinion life of 109cycles and a reliability of 0.98 What is full form of cid please help with this on the images WHERE ARE THE EXPERTS AND ACE!!!!!!! I NEED HELP PLS SHARE YO SMARTNESS!!!!! WILL GIVE BRAINLIEST AND RATE AND VOTE!!! EASY IM JUST NOT SMART PLEASE GIVE EXPLANATION Packagingthe material we use to put products inis everywhere, especially at grocery anddrug stores. Yogurt comes in plastic cups with aluminum tops covered by plastic lids. Razors arein plastic cases wrapped in cardboard. Packaging is importantit keeps food fresh and safe toeat. It protects products from damage. But its the greatest source of waste in many countriesaround the world.Packaging also hurts the environment. Packaging is made from many different materials.Some of these materials, such as plastic, contain chemicals that pollute water and soil (dirt) andare harmful to people and animals. In addition, to make packaging from paper, cardboard, andwood, people must cut down trees. Fewer trees can lead to climate change and other seriousenvironmental problems. So what can we do to reduce all this packaging?Everyone is concerned about packaging, including the people who use it the most,manufacturers, people that create and package products. In the past, they overused packaging.According to one government agency, manufacturers are beginning to reduce the amount ofpackaging that they use. CDs are an example. In the past, they came in large cardboardcontainers that were twice as big as the CDs inside them. Now, they come in small plastic boxes.Soft drink manufacturers are putting drinks into thinner bottles and cans that use less material.However, even though there is less waste from packaging, its still waste. We still have to dosomething with it. Heres what the average person can do: We can reduce the amount ofpackaging that we buy, and when we do buy it, we can reuse it. We can reduce the amount ofpackaging that we actually bring home by buying large-sized products that do more than onething, for example, laundry detergent that has fabric softener in it. We can reuse materials insteadof throwing them away. For example, we can use plastic or glass containers to store food, officesupplies, and other objects.Reducing and reusing are just two ways to limit waste from packaging. There are many otherways. Lets all work together to reduce waste!Which best describes the purpose and audience of this passage?Multiple Choiceto inform packaging manufacturers of new ways to reduce the size of their packagingto instruct government agencies in new ways to measure amounts of packagingto entertain consumers by describing problems caused by small amounts of packagingto persuade consumers to reduce the amount of packaging they use and throw away Which coordinate pair identifies a point in the third quadrant of the coordinate plane? A) (0, 5) B) (1, 5) C) (1, 5) D) (1, 2)(IF YOU USE THIS QUESTION FOR POINTS I WILL REPORT YOU)(NVM IT'S (-1,-2) True/False: Effective intercultural communication and cultural intelligence can help us to bring glory to God in our churches and in our ministries Which of the following are examples of physical properties of ethanol? Select all that apply.The boiling point is 78.37CIt is a clear, colorless liquidIt is flammableIt is a liquid at room temperature I NEED HELP ASAP!!! which of the following causes the magnetic force between the magnet and the scrap metal? The following data show the number of candies in 15 different bags.35, 48, 36, 48, 43, 37, 43, 39, 45, 46, 40, 35, 50, 38, 48 Implementing HTML best practices and writing code to match the original intentions of each element is known as __________ HTML. standard attribute-based industry semantic Why do the young men in the cattle car most likely bind, gag, and beat Mrs. Schchter? Select all that apply.Her screams and apparent hallucinations terrify the other prisoners.She refuses to stop complaining about the conditions on the train.The young men are eager to revolt against those who oppress them.She is being abusive to her son.They do not want to the morale of the prisoners to get any worse than it already is.Can be more than one answer Finish the following table for the given function with x as the independent variable A small emergency generator supplies 432 000 000 J of electrical energy in twenty-four hours. What is the average power output of the generator? Write the equation of the line for the graph shown below, please Tom and Carl start 200 miles apart, running towards each other. Tom runs 5 miles per hour faster than Carl. If they meet after 10 hours, how fast are they running? the expectation students often have when doing the coin flip experiment is that thye will flip exactly 5 heads and 5 tails because there is 50% chance of flipping each. Is this a realistic expectation A car moves 20 km towards the North and then 35 km at an angle of 60o towards west of North. Its magnitude of displacement from the initial position will be Heidi solved the equation 3(x + 4) + 2 = 2 + 5(x 4). Her steps are below:3x + 12 + 2 = 2 + 5x 203x + 14 = 5x 1814 = 2x 1832 = 2x16 = x