I really need help on this one

The price-earnings ratio for firms in a given industry follows the normal distribution. In this industry, a firm whose price-ear

lesantik [10]

Answer:

The correct answer is

A. 16%

Step-by-step explanation:

The zscore is used to solve problems of normally distributed samples.

This score indicates the percentage of a certain measure. It can be found looking at the z table.

For example, if a measure has a percentile of 75%, it is in the 100%-75% = highest 25 percent of all the measures.

$Z = 1$ has a pvalue 0.8413. So it is in the highest 1-0.8413 = 0.1587 = 16% percent of firms in the industry.

The correct answer is

A. 16%

4 0

3 years ago

A certain brand of jelly beans are made so that each package contains about the same number of beans. The filling procedure is n

pantera1 [17]

Answer:

p=0.063

Step-by-step explanation:

Let X be number of the certain brand of jelly beans that are made so that each package contains about the same number of beans.

X is N(375, 8)

YOu are collecting a sample size of

n = 8

Findings from the sample

$\bar x =370\\$

$H_0: \bar x =375\\H_a: \bar x$

(Left tailed test at 5% level)

Since sample size is small though sigma is known we use Z test, since norm

Mean difference = -5

Std error = $\frac{8}{\sqrt{8} } =2.828$

Test statistic t = mean diference / std error = $\frac{-5}{2.828} \\=-1.768$

df = n-1 =5

p value = 0.063

7 0

2 years ago

The time it takes for a planet to complete its orbit around a particular star is called the? planet's sidereal year. The siderea

BartSMP [9]

Answer:

(a) See below

(b) r = 0.9879

(c) y = -12.629 + 0.0654x

(d) See below

(e) No.

Step-by-step explanation:

(a) Plot the data

I used Excel to plot your data and got the graph in Fig 1 below.

(b) Correlation coefficient

One formula for the correlation coefficient is

$r = \dfrac{\sum{xy} - \sum{x} \sum{y}}{\sqrt{\left [n\sum{x}^{2}-\left (\sum{x}\right )^{2}\right]\left [n\sum{y}^{2} -\left (\sum{y}\right )^{2}\right]}}$

The calculation is not difficult, but it is tedious.

(i) Calculate the intermediate numbers

We can display them in a table.

x y xy x² y²

36 0.22 7.92 1296 0.05

67 0.62 42.21 4489 0.40

93 1.00 93.00 20164 3.46

433 11.8 5699.4 233289 139.24

887 29.3 25989.1 786769 858.49

1785 82.0 146370 3186225 6724

2797 163.0 455911 7823209 26569

3675 248.0 911400 13505625 61504

9965 537.81 1545776.75 25569715 95799.63

(ii) Calculate the correlation coefficient

$r = \dfrac{\sum{xy} - \sum{x} \sum{y}}{\sqrt{\left [n\sum{x}^{2}-\left (\sum{x}\right )^{2}\right]\left [n\sum{y}^{2} -\left (\sum{y}\right )^{2}\right]}}\\\\= \dfrac{9\times 1545776.75 - 9965\times 537.81}{\sqrt{[9\times 25569715 -9965^{2}][9\times 95799.63 - 537.81^{2}]}} \approx \mathbf{0.9879}$

(c) Regression line

The equation for the regression line is

y = a + bx where

$a = \dfrac{\sum y \sum x^{2} - \sum x \sum xy}{n\sum x^{2}- \left (\sum x\right )^{2}}\\\\= \dfrac{537.81\times 25569715 - 9965 \times 1545776.75}{9\times 25569715 - 9965^{2}} \approx \mathbf{-12.629}\\\\b = \dfrac{n \sum xy - \sum x \sum y}{n\sum x^{2}- \left (\sum x\right )^{2}} - \dfrac{9\times 1545776.75 - 9965 \times 537.81}{9\times 25569715 - 9965^{2}} \approx\mathbf{0.0654}\\\\\\\text{The equation for the regression line is $\large \boxed{\mathbf{y = -12.629 + 0.0654x}}$}$

(d) Residuals

Insert the values of x into the regression equation to get the estimated values of y.

Then take the difference between the actual and estimated values to get the residuals.

x y Estimated Residual

36 0.22 -10 10

67 0.62 -8 9

93 1.00 -7 8

142 1.86 -3 5

433 11.8 19 - 7

887 29.3 45 -16

1785 82.0 104 -22

2797 163.0 170 - 7

3675 248.0 228 20

(e) Suitability of regression line

A linear model would have the residuals scattered randomly above and below a horizontal line.

Instead, they appear to lie along a parabola (Fig. 2).

This suggests that linear regression is not a good model for the data.

4 0

2 years ago

On the graph shown, what is the slope ?

mr_godi [17]

Answer:

3/4

Step-by-step explanation:

To find the slope using a line on a graph, calculate the difference between two points. To do so, use the formula y2 - y1/x2 - x1.

Two points on this line are (0, -1) and (4, 2). This means:

y2 = 2

y1 = -1

x2 = 4

x1 = 0

Plugging those values in, we get:

2 - (-1)/4 - 0

Evaluating 2 - (-1) and 4 - 0, we get 3/4. Therefore, the slope is 3/4.

8 0

3 years ago

What is the arithmetic rule to the sequence: 1/3,4/3,7/3 find: f(10)

makkiz [27]

The the value of f(n)= $\frac{28}{3}$

Step-by-step explanation:

The Arithemetic sequence is given as a,a+d,a+2d......a(n-1)d

and f(n)=a(n-1)d

The given sequence is 1/3,4/3,7/3...

By comapring with Arithemetic sequence,

we get a=1/3

a+d=4/3

1/3 + d = 4/3

d=1

To find value of f(10):

take n=10

f(n)= $\frac{1}{3} +(10-1)1$

f(n)= $\frac{1}{3} +(9)1$

f(n)= $\frac{1+27}{3}$

f(n)= $\frac{28}{3}$

8 0

3 years ago