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3 years ago

11

PLZ HELP ME WITH THIS QUESTION!

1 answer:

Dima020 [189]3 years ago

4 0

Answer:

B

Step-by-step explanation:

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A professor went to a website for rating professors and looked up the quality rating and also the "easiness" of the six full-tim

Marat540 [252]

We are asked to determine the correlation factor "r" of the given table. To do that we will first label the column for "Quality" as "x" and the column for "Easiness" as "y". Like this:

Now, we create another column with the product of "x" and "y". Like this:

Now, we will add another column with the squares of the values of "x". Like this:

Now, we add another column with the squares of the values of "y":

Now, we sum the values on each of the columns:

Now, to get the correlation factor we use the following formula:

$r=\frac{n\Sigma xy-\Sigma x\Sigma y}{\sqrt{(n\Sigma x^2-(\Sigma x)^2)(n\Sigma y^2-(\Sigma y)^2)}}$

Where:

$\begin{gathered} \Sigma xy=\text{ sum of the column of xy} \\ \Sigma x=\text{ sum of the column x} \\ \Sigma y=\text{ sum of the column y} \\ \Sigma x^2=\text{ sum of the column x\textasciicircum2} \\ \Sigma y^2=\text{ sum of the column y\textasciicircum2} \\ n=\text{ number of rows} \end{gathered}$

Now we substitute the values, we get:

$r=\frac{\left(6)(70.56)-(25.2)(16.4\right)}{\sqrt{((6)(107.12)-(25.2)^2)((6)(47.82)-(16.4)^2)}}$

Solving the operations:

$r=0.858$

Therefore, the correlation factor is 0.858. If the correlation factor approaches the values of +1, this means that there is a strong linear correlation between the variables "x" and "y" and this correlation tends to be with a positive slope.

7 0

1 year ago

Mario invests £2000 for 3 years at 5% per annum compound interest. Calculate the value of the investment at the end of 3 years.

Delicious77 [7]

Answer:

$2315.25

Step-by-step explanation:

Given data

Principal= £2000

Time= 3 years

Rate= 5%

The compound interest expression is

A= P(1+r)^t

substitute

A= 2000(1+0.05)^3

A= 2000(1.05)^3

A= 2000*1.157625

A= 2315.25

Hence the Amount is $2315.25

7 0

3 years ago

From an industrial area 70 companies were selected at random and 45 of them were panning for expansion next year. Find 95% confi

Lana71 [14]

Answer:

Confidence limit = [52.8%, 75.2%]

Step-by-step explanation:

$P=\frac{45}{70}= 0.64$

$(1-P)=1-0.64=0.36$

$n= 70$

$P$ ± $z$ $\sqrt{\frac{P(1-P)}{n} }$

where the value $z$ will be taken from the z-table for 95% confidence interval

1-0.95= 0.05/2= 0.025

0.95+0.025= 0.0975

From the z-table the value of $z$ corresponding to 0.0975 is 1.96

$0.64$ ± $1.96$ $\sqrt{\frac{0.64*0.36}{70} }$

$0.64$ ± $1.96$ $(0.057)$

$0.64$ ± $0.112$

$64%$ % ± $11.2$ %

so the confidence interval is

$64+11.2=75.2$ %

$64-11.2=52.8$ %

$[52.8, 75.2]$

8 0

3 years ago

In triangle abc, cos A= -0.6. Find A and Tan A

Tresset [83]

Answer:

Part 1) $A=126.87^o$

Part 2) $tan(A)=-\frac{4}{3}$

Step-by-step explanation:

we have

$cos(A)=-0.6$

The cos(A) is negative, that means that the angle A in the triangle ABC is an obtuse angle and the value of the sin(A) is positive

The angle A lie on the II Quadrant

step 1

Find the measure of angle A

$cos(A)=-0.6$

using a calculator

$A=cos^{-1}(-0.6)=126.87^o$

step 2

Find the sin(A)

we know that

$sin^2(A)+cos^2(A)=1$

substitute the value of cos(A)

$sin^2(A)+(-0.6)^2=1$

$sin^2(A)=1-0.36$

$sin^2(A)=0.64$

$sin(A)=0.8$

step 3

Find tan(A)

we know that

$tan(A)=\frac{sin(A)}{cos(A)}$

substitute the values

$tan(A)=\frac{0.8}{-0.6}$

Simplify

$tan(A)=-\frac{4}{3}$

5 0

3 years ago

BRAINLIEST ANSWER! I need help

sladkih [1.3K]

The equation would be 6(x+15)
The answer would be -22

4 0

3 years ago