Project #84556 - stats225hw1

#2

The formula for a regression equation is Y’ = 2X + 9.

a.What would be the predicted score for a person scoring 6 on X?

b.If someone’s predicted score was 14, what was this person’s score on X?

 

#6

For the X,Y data below, compute:

 

a. r and determine if it is significantly different from zero.

b. the slope of the regression line and test if it differs significantly from zero.

c. the 95% confidence interval for the slope.

 

 #5

At a school pep rally, a group of sophomore students organized a free raffle for prizes. They claim that they put the names of all of the students in the school in the basket and that they randomly drew 36 names out of this basket. Of the prize winners, 6 were freshmen, 14 were sophomores, 9 were juniors, and 7 were seniors. The results do not seem that random to you. You think it is a little fishy that sophomores organized the raffle and also won the most prizes. Your school is composed of 30% freshmen, 25% sophomores, 25% juniors, and 20% seniors.

 

a. What are the expected frequencies of winners from each class?

b. Conduct a significance test to determine whether the winners of the prizes were distributed throughout the classes as would be expected based on the percentage of students in each group. Report your Chi Square and p values.

c. What do you conclude?

 

#14

A geologist collects hand-specimen sized pieces of limestone from a particular area. A qualitative assessment of both texture and color is made with the following results. Is there evidence of association between color and texture for these limestones? Explain your answer

 

 

Colour

Texture

Light

Medium

Dark

Fine

4

20

8

Medium

5

23

12

Coarse

21

23

4

  

#70

The standard deviation of the chi-square distribution is twice the mean.  (T/F)

#102

Do men and women select different breakfasts? The breakfasts ordered by randomly selected men and women at a popular breakfast place is shown in Table. Conduct a test for homogeneity at a 5% level of significance.

 

 

French Toast

Pancakes

Waffles

Omelets

Men

47

35

28

53

Women

65

59

55

60

 

                                                                                           

#113

Suppose an airline claims that its flights are consistently on time with an average delay of at most 15 minutes. It claims that the average delay is so consistent that the variance is no more than 150 minutes. Doubting the consistency part of the claim, a disgruntled traveler calculates the delays for his next 25 flights. The average delay for those 25 flights is 22 minutes with a standard deviation of 15 minutes

 

df = ________

 

#117 (cont. from #113)

Let α = 0.05 Decision: ________

Conclusion (write out in a complete sentence.): ________

 

#66

Can a coefficient of determination be negative? Why or why not?

 
#82

Size (ounces)

Cost ($)

Cost per ounce

16

3.99

 

32

4.99

 

64

5.99

 

200

10.99

 

a. Using “size” as the independent variable and “cost” as the dependent variable, draw a scatter plot.
b. Does it appear from inspection that there is a relationship between the variables? Why or why not?
c. Calculate the least-squares line. Put the equation in the form of: Å· = a + bx
d. Find the correlation coefficient. Is it significant?
e. If the laundry detergent were sold in a 40-ounce size, find the estimated cost.
f. If the laundry detergent were sold in a 90-ounce size, find the estimated cost.
g. Does it appear that a line is the best way to fit the data? Why or why not?
h. Are there any outliers in the given data?
i. Is the least-squares line valid for predicting what a 300-ounce size of the laundry detergent would you cost? Why or why not?
j. What is the slope of the least-squares (best-fit) line? Interpret the slope

 

Subject Mathematics
Due By (Pacific Time) 10/03/2015 11:57 pm
Report DMCA
TutorRating
pallavi

Chat Now!

out of 1971 reviews
More..
amosmm

Chat Now!

out of 766 reviews
More..
PhyzKyd

Chat Now!

out of 1164 reviews
More..
rajdeep77

Chat Now!

out of 721 reviews
More..
sctys

Chat Now!

out of 1600 reviews
More..
sharadgreen

Chat Now!

out of 770 reviews
More..
topnotcher

Chat Now!

out of 766 reviews
More..
XXXIAO

Chat Now!

out of 680 reviews
More..
All Rights Reserved. Copyright by AceMyHW.com - Copyright Policy