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Problem 1 : The table below contains the value of the house and the amount of rental income in a year that the house brings

Problem 1:

The table below contains the value of the house and the amount of rental income in a year that the house brings in when rented. Answer all parts (a) through (e).

(a) Create a scatter plot of the data. What kind of association does the scatter plot suggest (e.g., positive linear, etc.)

(b) Using technology (e.g., Excel's Regression Tool or the TI 84 calculator), determine the following:

(i) Find the linear correlation coefficient "r". Provide an interpretation.

(ii) Find the coefficient of determination "R2". Provide an interpretation.

(iii) Find the equation of the least squares regression line between the value of the house and the amount of rental income in a year that the house brings in when rented.

(c) Using the equation from part (b)(iii), find the following:

(i) Estimate the rental income for a house worth $230,000;

(ii) Estimate the rental income for a house worth $400,000.

(d) Which rental income that you calculated in part(c) is a more accurate estimate of the true rental income? Why?

(e) Test at the 5% level for a positive correlation between house value and rental amount. Specifically, do the following:

(i) Set up the appropriate null and alternative hypotheses.

(ii) Verify that the assumptions necessary to apply the test are satisfied.

(iii) What is the test statistic and what is the p-value?

(iv) State your conclusion.

Table: Data of House Value versus Rental

Value Rental Value Rental Value Rental Value Rental
81000 6656 77000 4576 75000 7280 67500 6864
95000 7904 94000 8736 90000 6240 85000 7072
121000 12064 115000 7904 110000 7072 104000 7904
135000 8320 130000 9776 126000 6240 125000 7904
145000 8320 140000 9568 140000 9152 135000 7488
165000 13312 165000 8528 155000 7488 148000 8320
178000 11856 174000 10400 170000 9568 170000 12688
200000 12272 200000 10608 194000 11232 190000 8320
214000 8528 208000 10400 200000 10400 200000 8320
240000 10192 240000 12064 240000 11648 225000 12480
289000 11648 270000 12896 262000 10192 244500 11232
325000 12480 310000 12480 303000 12272 300000 12480

Problem 2:The World Bank collected data on the percentage of GDP that a country spends on health expenditures and also the percentage of women receiving prenatal care. The data for the countries where this information are available for the year 2011 is in the table below. Answer all parts (a) through (e).

(a) Create a scatter plot of the data. What kind of association does the scatter plot suggest (e.g., positive linear, etc.)

(b) Using technology (e.g., Excel's Regression Tool or the TI 84 calculator), determine the following:

(i) Find the linear correlation coefficient "r". Provide an interpretation.

(ii) Find the coefficient of determination "R2". Provide an interpretation.

(iii) Find the equation of the least squares regression line between percentage spent on health expenditures and the percentage of women receiving prenatal care.

(c) Using the equation from part (b)(iii), find the following:

(i) Estimate the percent of women receiving prenatal care for a country that spends 5.0% of GDP on health expenditures;

(ii) Estimate the percent of women receiving prenatal care for a country that spends 12.0% of GDP on health expenditures.

(d) Which prenatal care percentage that you calculated in part (c) do you think is closer to the true percentage? Why?

(e) Test at the 5% level for a correlation between percentage spent on health expenditures and the percentage of women receiving prenatal care. Specifically, do the following:

(i) Set up the appropriate null and alternative hypotheses.

(ii) Verify that the assumptions necessary to apply the test are satisfied.

(iii) What is the test statistic and what is the p-value?

(iv) State your conclusion.

Table: Data of Health Expenditure versus Prenatal Care

Health Expenditure (% of GDP) Prenatal Care (%)
9.6 47.9
3.7 54.6
5.2 93.7
5.2 84.7
10.0 100.0
4.7 42.5
4.8 96.4
6.0 77.1
5.4 58.3
4.8 95.4
4.1 78.0
6.0 93.3
9.5 93.3
6.8 93.7
6.1 89.8

Problem 3:

Researchers watched groups of dolphins off the coast of Ireland in 1998 to determine what activities (travel, feed, social) the dolphins partake in at certain times of the day. The numbers in the table below represent the number of groups of dolphins that were partaking in an activity at certain times of days.

Set up and run a test of hypothesis to determine ifthere is enough evidence to show that the activity and the time period are independent for dolphins. Use a level of significance of 1%. Specifically, do the following:

(i) Write down the null and alternative hypotheses.

(ii)Verify that the assumptions necessary to apply the test are satisfied.

(iii) What is the test statistic and what is the p-value?

(iv) State your conclusion

Table: Dolphin Activity

Activity

Period

Row

Total

Morning Noon Afternoon Evening
Travel 6 6 14 13 39
Feed 28 4 0 56 88
Social 38 5 9 10 62
Column Total 72 15 23 79 189

Problem 4.

A person's educational attainment and age group were collected by the U.S. Census Bureau in 1984 to see if age group and educational attainment are related. The counts in thousands are in the table below.

Set up and run a test of hypothesis to determine ifthere is enough evidence to show that educational attainment and age are independent. Use a level of significance of 5%. Specifically, do the following:

(i) Write down the null and alternative hypotheses.

(ii)Verify that the assumptions necessary to apply the test are satisfied.

(iii) What is the test statistic and what is the p-value?

(iv) State your conclusion

Table: Educational Attainment and Age Group

Education

Age Group Row Total
25-34 35-44 45-54 55-64 >64
Did not complete HS 5416 5030 5777 7606 13746 37575
Competed HS 16431 1855 9435 8795 7558 44074
College 1-3 years 8555 5576 3124 2524 2503 22282
College 4 or more years 9771 7596 3904 3109 2483 26863
Column Total 40173 20057 22240 22034 26290 130794

Problem 5.

In Africa in 2011, the number of deaths of a female from cardiovascular disease for different age groups are in the table below. Also, the proportion of deaths of females from all causes for the same age groups are in the table.

Set up and run a test of hypothesis to determine ifdeaths from cardiovascular disease are in the same proportion as all deaths for the different age groups. Use a level of significance of 5%. Specifically, do the following:

(i) Write down the null and alternative hypotheses.

(ii)Verify that the assumptions necessary to apply the test are satisfied.

(iii) What is the test statistic and what is the p-value?

(iv) State your conclusion

Table: Deaths of Females for Different Age Groups

Age Cardiovascular Frequency All Cause Proportion
"5 - 14" 8 0.10
"15 - 29" 16 0.12
"30 - 49" 56 0.26
"50 - 69" 433 0.52
TOTAL 513

Problem 6.

A project conducted by the Federal Office of Road Safety asked people many questions about their cars. One question asked was: "What is the primary reason that a person chooses a particular car?" The data is contained in the table below.

Table: Reason for Choosing a Car

SAFETY 84
RELIABILITY 62
COST 46
PERFORMANCE 34
COMFORT 47
LOOKS 27
TOTAL 300

Set up and run a test of hypothesis to determine ifthe frequencies observed substantiate the claim that the reasons for choosing a car are equally likely. Use a level of significance of 5%. Specifically, do the following:

(i) Write down the null and alternative hypotheses.

(ii)Verify that the assumptions necessary to apply the test are satisfied.

(iii) What is the test statistic and what is the p-value?

(iv) State your conclusion

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