Raw scores on behavioral tests are often transformed for easier comparison. A test of reading ability has mean 67 and standard deviation 10 when given to third graders. Sixth graders have mean score 86 and standard deviation 9 on the same test. To provide separate "norms" for each grade, we want scores in each grade to have mean 100 and standard deviation 20. (Round your answers to two decimal places.)
(a) What linear transformation will change third-grade scores x into new scores xnew = a + bx that have the desired mean and standard deviation? (Use b > 0 to preserve the order of the scores.) a = b = (b)
Do the same for the sixth-grade scores.
a =
b =
(c) David is a third-grade student who scores 79 on the test. Find David's transformed score.
Nancy is a sixth-grade student who scores 79. What is her transformed score?
Who scores higher within his or her grade? Nancy or David

Answers

Answer 1

Answer:

a.) a = -34 and b = 2

b.) a = -91.11 b = 2.22

c.) David scored 124, nancy scored 84.27

David scored higher

Step-by-step explanation:

for those in the 3rd grade

mean u = 67

s = 10

we used the z formula

[tex]z=\frac{x-u}{s}[/tex]

[tex]z=\frac{x-67}{10}[/tex]

we have the new score

u = 100

s = 20

we use this formula [tex]z*s+u[/tex]

[tex][\frac{x-67}{10} ]20\\[/tex] + 100

multiply through by 20

[tex][\frac{20x-1340}{10} ] +100[/tex]

dividing the bracket by 10

= [tex]2x-134+100[/tex]

= [tex]2x-34[/tex]

from this solution above,

a = -34 and b = 2

b.)

we solve for those in the 6th grade

u = 86

s = 9

[tex]\frac{x-86}{9}[/tex]

for new score,

y = 100

s = 20

[tex][\frac{x-86}{9} ]20+100[/tex]

[tex]2.22x-191.11+100\\= 2.22x - 91.11[/tex]

from this solution

a = -91.11

b = 2.22

c.) if David scored 79

[tex]= 2(x)-34[/tex]

= 2(79) - 34

= 158 - 34

= 124

if nancy scored 79

= 2.22(79) - 91.11

= 175.38 - 91.11

= 84.27

from these scores we can see that David scored higher in his grade


Related Questions

If can someone help me.

Answers

9514 1404 393

Answer:

  Tim is correct. 5/8 > 1/2

Step-by-step explanation:

By taking 5/8 of the lasagna, Tim will be taking more than half (4/8) of it. No remaining share can be larger. Any remaining share will be 3/8 or less, so will be smaller than a 5/8 share.

Tim's 5/8 share is the largest.

Express it in slop-intercept form​

Answers

Answer:

y = ½x -3

Step-by-step explanation:

_____________________

Part B: Find an irrational number that is between 9.5 and 9.7. Explain why it is irrational. Include the decimal approximation of the irrational number to the nearest hundredth. (3 points)

Answers

Answer: Part A: Find a rational number that is between 9.5 and 9.7. Explain why it is rational.

Step-by-step explanation:

Part B: Find an irrational number that is between 9.5 and 9.7. Explain why it is irrational. Include the decimal approximation of the irrational number to the nearest hundredth

You can copy the data into Excel by highlighting the data, right-clicking and selecting Copy, then opening Excel, clicking on a blank cell, and selecting Paste from the Edit menu. Give your answers to at least 3 decimal places accuracy. Keep the data in Excel and keep the answers below handy, as you will need this information again in later questions. 2. Compute the following summary statistics a) The mean for the low income group is: b) The median for the low income group is: c) The standard deviation for the low income group is: d) The mean for the high income group is: e) The median for the high income group is: f) The standard deviation for the high income group is:

Answers

Answer:

Low income group :

Mean = 22.100

Median = 22.000

Standard deviation = 4.717

High Income group :

Mean = 19.771

Median = 20.000

Standard deviation = 3.255

Step-by-step explanation:

Low income : 19,20,13,28,21,27,16,21,19, 19,34,24, 24,14,24,25,23,22,20,21,14,23,17,26,24,24,20,24,27,16,22,17,29,20,25,22,20,34,24,22

High Income : 23 19 19 18 20 18 17 25 13 24 25 17 21 19 17 22 22 15 19 23 19 23 22 20 20 20 13 21 16 13 21 24 23 21 20

Using Excel :

Mean of low income, Σx / n = 884/40 = 22.100

Median of low income group : 1/2(n+1)th term = Median of low income = 22.000

Standard deviation of low income group :

√(Σ(x - mean)²/n) = 4.717

High Income group :

Mean of high income, Σx / n = 692/35 = 19.771

Median of high income group : 1/2(n+1)th term = Median of high income = 20.000

Standard deviation of low income group :

√(Σ(x - mean)²/n) = 3.255

simplify the expression
7y − (6)2y − 12

Answers

Answer:

-5y-12

Step-by-step explanation:

Multiply 6 into 2y

7y-12y-12

-5y-12

He’s right the guy on top

What is the quotient when (-12x9 + 3x7 + 24x6) is divided by 6x?

Answers

-2x^8+.5x^6+4x^5 is the quotient.

if x varies directly as y,write a formula connecting x and y y.use k as a constant of variaton.​

Answers

x = ky

Here, x varies directly as y and k is the constant of variation, so x is equal to k multiplied by y

How many solutions are there for the system of equations shown on the graph?

A coordinate plane is shown with two lines graphed. One line crosses the y axis at 3 and has a slope of negative 1. The other line crosses the y axis at 3 and has a slope of two thirds.

No solution
One solution
Two solutions
Infinitely many solutions

Answers

The lines intersect in two different points, so the system has two solutions. d. The graphs of the two equations are the same line, so there are infinitely many solutions.

HELLLLLLLPPPPPPPPPPPP

Answers

Answer:

250

5:15

true

i already helped you

Answer:

9- 4 hours 30 minutes

10- 250

11- False

Find the value of x

(it needs to be 20 characters so don’t mind the extra ness ………..)

Answers

x=120

180-46-74= 60
180-60= 120

If Terry gives 30% of his sweets to Alex,they will have the same number of sweets.If terry gives 750 of his sweets to Alex,then Alex will have 80% more sweets than Terry.How many sweets does Terry have?

Answers

Answer:

Terry has 1500 sweets.

Step-by-step explanation:

This question is solved using a system of equations.

I am going to say that:

x is the number of sweets Terry has.

y is the number of sweets Alex has.

If Terry gives 30% of his sweets to Alex,they will have the same number of sweets.

This means that:

[tex](1 - 0.3)x = y + 0.3x[/tex]

[tex]0.7x = y + 0.3x[/tex]

[tex]y = 0.4x[/tex]

If Terry gives 750 of his sweets to Alex,then Alex will have 80% more sweets than Terry.

This means that:

[tex]y + 750 = 1.8(x-750)[/tex]

We want to find x, and since [tex]y = 0.4x[/tex]

[tex]y + 750 = 1.8x - 1350[/tex]

[tex]0.4x + 750 = 1.8x - 1350[/tex]

[tex]1.4x = 2100[/tex]

[tex]x = \frac{2100}{1.4}[/tex]

[tex]x = 1500[/tex]

Terry has 1500 sweets.

A bicycle has a listed price of 593.98 before tax. If the sales tax rate is 9.5%, find the total cost of the bicycle with sales tax included. Round your answer to the nearest cent, as necessary.​

Answers

Answer:

the answer is in  

Step-by-step explanation:

Choose the equation for the line that passes through (6, 5) and is parallel to the line x + 3y = 9.

Answers

Answer:

y = -1/3x + 7

Step-by-step explanation:

x + 3y = 9 ⇒ y = -1/3x + 3

Use point-slope form and substitute the values:

[tex]y-y_1=m(x-x_1)\\y-5=-\frac{1}{3}(x-6)\\y-5=-\frac{1}{3}x+2\\y=-\frac{1}{3}x+7[/tex]

Given that ZABC = ZDBE, which statement must be
true?
ZABC - ZABD
ZABD Z CBE
Z CBD , ZDBE
Z CBD - ZABC

Answers

Answer:

B abd = cbe

Step-by-step explanation:

ABC = DBE

so

ABC + CBD = DBE + CBD

The statement which is true is ZABC - ZABD, the correct option is A.

What is a solution to a system of equations? (SOLUTION GRAPHICALLY)

For a solution to be solution to a system, it must satisfy all the equations of that system, and as all points satisfying an equation are in their graphs, so solution to a system is the intersection of all its equation at single point(as we need common point, which is going to be intersection of course)(this can be one or many, or sometimes none)

We are given that;

Angle ABC = Angle DBE

Now,

A flowchart proof is a formal proof that is set up with boxes that flow from one to the next with arrows1. The statements, which are true facts that we know, are placed in the boxes, with the reason we know them on a line underneath2. We can prove theorems are true using flowchart proofs.

To justify each step in the flowchart proof, we have to provide a reason for each statement based on definitions, postulates, properties or previously proven theorems. Here is how we can fill in the blanks:

A: Given B: Definition of angle bisector C: Definition of congruent angles

Therefore, graphically the answer will be ZABC - ZABD.

Learn more about finding the solution graphically here:

https://brainly.com/question/26254258

#SPJ7

Kevin was asked to determine the length of side XZ. His work is shown.

Which error did Kevin make?

Answers

Answer:

A.// He has the side lengths in the wrong place in the cosine ratio.

Step-by-step explanation:

nd interest for a loan
To pay for an $18,900 truck, Joe made a down payment of $3600 and took out a loan for the rest. On the loan, he paid monthly payments of $338.67 for 4
years.

Answers

Answer: He will pay this amount, with interest, over a 4-year period payment that he must make After paying 20% as a down payment, they finance the Determine the monthly payments needed to amortize the loan and months, that payments can be made under each of the following options before the money runs out.

Step-by-step explanation:

The function ƒ(x) = −(x + 3)^2 − 4 is not one-to-one. Find a portion of the domain where the function is one-to-one and find an inverse function.

Answers

Answer:

Step-by-step explanation:

The second one I believe.

A manufacturer claims that the mean lifetime,u , of its light bulbs is 51 months. The standard deviation of these lifetimes is 7 months. Sixty bulbs are selected at random, and their mean lifetime is found to be 53 months. Can we conclude, at the 0.1 level of significance, that the mean lifetime of light bulbs made by this manufacturer differs from 51 months?
Perform a two-tailed test. Then fill in the table below.
Carry your intermediate computations to at least three decimal places, and round your responses as specified in the table. (If necessary, consult a list of formulas.)
the null hypothesis:
The alternative hypotehsis:
The type of test statistic (choose Z, t, Chi-square, or F)
The value of the test statistic (round to at least three decimal places:
Can we conclude that the mean lifetime of the bulbs made by this manufacture differ from 51 months?

Answers

Answer:

We reject  H₀, and conclude thet the mean lifetime of the bulbs differ from 51 month

Step-by-step explanation:

Manufacturing process under control must produce items that follow a normal distribution.

Manufacturer information:

μ  =  51 months     mean lifetime

σ  =  7 months       standard deviation

Sample Information:

x  =  51 months

n  =  60

Confidence Interval  =  90 %

Then significance level  α  =  10 %  α  =  0.1    α/2  =  0,05

Since it is a manufacturing process the distribution is a normal distribution, and with   n = 60 we should use a Z test on two tails.

Then from z- table z(c) for  α = 0,05  is  z(c)  = 1.64

Hypothesis  Test:

Null Hypothesis                              H₀            x  =  μ

Alternative Hypothesis                  Hₐ            x ≠  μ

To calculate z statistics  z(s)

z(s)  =   (  x   -  μ )  / σ /√n

z(s)  =   (  53  -  51 ) / 7 /√60

z(s)  =  2 * 7.746 / 7

z(s)  = 2.213

Comparing  z(s)  and  z(c)

z(s)  >  z(c)   then  z(s)  is in the rejection region

We reject  H₀, and conclude thet the mean lifetime of the bulbs differ from 51 month

a purchasing agent for kelly bread company wants to estimate the mean daily usage of rye flour. she takes a sample for 50 straight days and finds that the sample mean is 180 pounds with a sample standard deviation of 38.5 pounds. State the 90% confidence interval for the mean

Answers

Answer:

The 90% confidence interval for the mean is (170.87 , 189.13)

Step-by-step explanation:

Using the calculator we can easily calculate   the 90% confidence interval for the mean, the given values are:

mean=180

sx : 38.5

n : 50

c - Level : 0.90

Then the output will be [170.87 , 189.13]

Create a data set such that the median is 19 the mode is 24 the mean is 25

Answers

Answer:

-80, 4, 5, 6, 19, 24, 24, 24, 24

I will give BRAINLIEST to whoever answers correctly first!!!

Sophie wants to buy a pair of scissors that cost $1.82. If she gives the cashier a five dollar bill, how
much change should she get back?

Answers

$3.18

Explanation: I am a cashier hahaha

Answer:

Sophie will get $3.18 back in change.

Step-by-step explanation:

You do 5.00-1.82 and you get 3.18, which is equal to the change that Sophie will get.

find the constant of variation for the relation and use it to write an equation for the statement. Then solve the equation. if y varies directly as X and Z, and t=8/3 when x=1 and z=4, find y when x=6 and z=3

Answers

Answer:

The Question isn't clear

Step-by-step explanation:

Answer:

can someone please answer this question correctly for me. i need it asap

Step-by-step explanation:

Identifying a Proportional Relationship in a Table
Which takle represents a proportional relationship?
x
y
4
*
.
09
y
8
5
2
12
7
18
20
26
12
28
60
84
18
20

Answers

9514 1404 393

Answer:

  see below

Step-by-step explanation:

A proportional relationship is one in which the ratio of y to x is a constant for all non-zero values of x and y.

Of the tables shown here, this is the case only for the one shown below. It has ...

  y = 1.4x

Answer:

The middle one

Step-by-step explanation:

The middle one

y = (7/5)x

 x       y

 5      7

20    28

60    84

0.01 0.03 0.09 0.35 0.41 0.41 0.41 0.42 0.54 0.57 0.71 0.77 0.83 0.87 0.93 0.95 0.99 1.01 1.01 1.09 1.12 1.33 1.34 1.45 1.48 1.49 1.54 1.65 1.73 1.82 1.87 1.95 1.99 2.02 2.03 2.16 2.32 2.33 2.35 2.46 2.48 2.55 2.61 2.62 2.63 2.69 2.72 2.72 2.85 2.96
find the median

Answers

Step-by-step explanation:

[tex]median = \frac{1.48 + 1.49}{2} [/tex]

[tex] = \frac{2.97}{2} [/tex]

[tex] = 1.485[/tex]

Exercise 5.2
Which of the capital letters of the English alphabet are symmetrical?​

Answers

Answer:

The Capital letter of English alphabet that are symmetric are B,C,D,E,H,I,K,OX

Step-by-step explanation:

hope it helps

Pls help school is almost over

Answers

Answer:

correct answer is c

Step-by-step explanation:

2.44x10^-3

Pleaseee helpppp!!! 20 points

Answers

Answer:

The correct option is (A).

Step-by-step explanation:

The given expression is :

[tex]\dfrac{14x^4y^6}{7x^8y^2}[/tex]

The numerator contains 14x⁴y⁶ and the denominator is 7x⁸y².

We can write it as :

[tex]\dfrac{14x^4y^6}{7x^8y^2}=\dfrac{7\times 2\times x^4\times y^2\times y^4}{7x^4\times x^4\times y^2}[/tex]

Canceling the common terms,

[tex]=\dfrac{2y^4}{x^4}[/tex]

So, the correct option is (A).

A union of restaurant and foodservice workers would like to estimate the mean hourly wage, , of foodservice workers in the U.S. The union will choose a random sample of wages and then estimate using the mean of the sample. What is the minimum sample size needed in order for the union to be confident that its estimate is within of

Answers

Answer:  the minimum sample size needed = 145

Step-by-step explanation:

Formula for sample size:

[tex]Sample \ size =(\dfrac{z^*\times standard\ deviation}{margin \ of \ error})^2[/tex]

, where z* = Critical z-value

Given: Standard deviation = 2.15

Margin of error = 0.35

Z* for 95% confidence = 1.96

Sample size = [tex](\frac{1.96\times2.15}{0.35})^2[/tex]

[tex]=(12.04)^2\\\\=144.9616\approx145[/tex]

Hence, the minimum sample size needed = 145

HELPP what is the area of this cylinder

Answers

Answer:

1,884

Step-by-step explanation:

The formula for solving the area of a right cylinder like this one is:

=2πrh+2πr2

Note:

Pls notify me if my answer is incorrect for the other users that will see this response. Thank you.

-kiniwih426


If 80 persons can perform a piece of work in 16 days of 10 hours each, how
many men will perform a piece of work twice as great in tenth part of the time
working 8 hours a day supposing that three of the second set can do as much
work as four of the first set?

Answers

Answer:

The number of men needed to perform a piece of work twice as great in tenth part of the time  working 8 hours a day supposing that three of the second set can do as much  work as four of the first set is:

1200 men.

Step-by-step explanation:

To find the answer, first, we're gonna find how many hours take to make the piece of work in 16 days, taking into account each day just has 10 hours:

Number of hours to make a piece of work = 16 * 10 hoursNumber of hours to make a piece of work = 160 hours.

Now, we divide the total hours among the number of persons:

Equivalence of hours per person = 160 hours / 80 persons.Equivalence of hours per person = 2 hours /person

This equivalence isn't the real work of each person, we only need this value to make the next calculations. Now, we have a piece of work twice as great as the first, then, we can calculate the hours the piece of work needs to perform it (twice!):

Number of hours to make the second piece of work = 160 hours * 2Number of hours to make the second piece of work = 320 hours

We need to make this work in tenth part of the time working 8 hours a day, it means:

Time used to the second work = 320 hours / 10Time used to the second work = 32 hours Time used to the second work = 32 hours / 8 hours (as each day has 8 hours)Time used to the second work = 4 days

Now, we know three of the second set can do as much  work as four of the first set, taking into account the calculated equivalence, we have:

Work of four workers of first set = Work of three workers of second setWork of four workers of first set = Equivalence * 4 persons.Work of four workers of first set = 2 hours /person * 4 personsWork of four workers of first set = 8 hours.

So, three persons of the second set can make a equivalence of 8 hours. At last, we calculate all the number of workers we need in a regular time:

Number of needed workers in a regular time = (320 hours / 8 hours) * 3 persons.Number of needed workers in a regular time = 40 * 3 personsNumber of needed workers in a regular time = 120 persons

Remember we need to perform the job not in a regular time, we need to perform it in tenth part of the time, by this reason, we need 10 times the number of people:

Number of needed workers in tenth part of the time = 120 persons * 10Number of needed workers in tenth part of the time = 1200 persons

With this calculations, you can find the number of men needed to perform a piece of work twice as great in tenth part of the time  working 8 hours a day supposing that three of the second set can do as much  work as four of the first set is 1200 persons.

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