Statistics

Homework week 6

1. (11.9 pg. 409) The following data represents the price of regular gasoline at self service stations in four counties in New York City May 17, 2014

                Manhatten

               Bronx

            Queens

              Brooklyn

           nassau

                 Suffolk

2.339

2.199

2.239

2.159

2.099

2.179

2.299

2.139

2.239
2.199
2.199
2.159
2.239
2.239
2.179

2.359

2.259

2.119

2.199
2.159
2.299
2.159
2.239
2.159
2.199
2.179

2.279

1.999

2.239

2.219

At the .05 level of significance, is there evidence of a difference in the mean price of gasoline in the six counties

a. State the null hypothesis, state the alternative hypothesis

b. using excel, analyze the gas data using the ANOVA:single factor 

c. explain your results comparing the F results to Fcritical and how this determines whether we can accept or reject Ho.  What is your conclusion from this analysis.

2. (12.5 pg. 452) A sample of

500

shoppers was selected in a large metropolitan area to determine various information concerning consumer behavior. Among the questions asked was “Do you enjoy shopping for clothing?” the results  are summarized in the following contingency table

GENDER

Enjoy Shopping for Clothing

     Male

 Female

    

Total

 

yes

136

224

360

no

104

36

140

Total

240

260

500

a. Is there evidence of a significant difference between the proportion of males and females who enjoy shopping for clothing at the .01 level of significance?  Watch the video provided to do this problem in Excel.

c. What is your answer to a) if 206 males enjoyed shopping for clothing 

Class Work week 6 problem.xlsx

February 21 2020, 3:33 PM

2

>#

4

Ch.

1

1

ood Company has a business objective of expanding its product line beyond its current kidney and shrimp based cat foods. The company developed two new products, one based on chicken liver and the other based on

. The company conducted an experiment to compare the two new products with its two existing ones, as well as generic beef-based products sold at a supermarket chain. For the experiment, a sample of

cats from the population at a local animal shelter was selected. Ten cats were randomly assigned to each of the rive products being tested. each of the cats was then presented with

ouncesif the selected foodin a dish feeding time. The researchers defined the variable to be within a

minute time interval that began when the filled dish was presented.

cats

Salmon

n=50

s

Kidney 10

.56

76

2.25 2.26

Shrimp 10

9

2.62 2.37

Chicken Liver 10

8

2.34

2.37 1.96

Salmon 10

.28

44177778

2.47

2.26

Beef 10

2.45 2.36 2.45

2.59

, is there a difference in the mean amount of food eaten

F

4

2083

45

49

Group

Comparison

1

2

3

4

5

0.05

																																																																																																																		Pet	F		Salmon	5											0		3									10
	n=50
10 cats were randomly assigned to each of the 5 products.
They were presented food at ac ertain feeding time and measured the amount of food in ounces in 10 minute intervals
	Kidney		Shrimp		Chicken Liver		Beef	Anova: Single Factor
		2.37			2.	2		6	2.29	1.79	2.09	c= 5 groups
	2.62	2.69	2.23	2.33	1.87	SUMMARY
2.31		2.25	2.41		1.96	1.67		Group	Count	Sum	Average	Variance
	2.47			2.	45	2.68	2.05	1.64		24	2.456	0.0			14
	2.59		2.34	2.	16	24.09	2.	40	0.0253433333
2.17	2.24	1.75	23.68		2.36	0.0262844444
2.	22	1.18			20	2.028			0.05
2.56	1.58	1.92	17.54	1.754	0.0990266667
2.18	1.	32
2.32	2.57	1.93	1.94
ANOVA
a. at the 0.05	level of significance	Source of Variation	SS		df	MS	P-value	F crit
among the various products	Between Groups	3.65896	0.91474	20.8054	12	0.0000000009	2.5787391843
state your null hypothesis and it would be a good idea to list your variables	Within Groups	1.978	49	0.0439664444
Total	5.63745
b. If appropriate, which test would you use to determine which products appear to differ significantly in the mean amount of food eaten
Tukey- Kramer	Comparison
Sample Mean	Sample Size	Absolute Differece	Std. Error	Critical Range	Results
Group1 to Group2
G1 to G3
G1 to G4
G1 to G5
Group 2 to G3
Other	Data	G2 to G4
Level of Significance	G2 to G5
Numerator d.f	Group 3 to G4
Denominator d.f.	G3 to G5
Q statistic	Group 4 to G5

#6 Ch.12

20 10

0

24 32 14

22 26 12

10 14 6

14 16 10 40

70

Number of Meals per week
Class Standing 20 10 none total
freshman 0
sophmore 0
junior 0
senior 0
0 0 0 0
Data
level of significance 0.05

4

3

df 6

0 0

OBSERVED	observed values
	Number of Meals per week	fo-fe
	Class Standing		none		total
	freshman		70
	sophmore	60
	junior	30
	senior
88	42	200
EXPECTED FREQUENCIES	Expected values
Number of Rows
Number of Columns
Critical value	12.5915872437
Chi-squared test statistic