Question 1

Use the information in nhanes1.sav. You should use SPSS to calculate the sample statistics you will need to do this question, but for parts (a) and (c) you are required to do the rest of the calculations by hand, using a calculator.

(a) Construct a 95% confidence interval for the population mean amount of money spent at the supermarket in the last 30 days (CBD070) (show all working).

(b) Check the appropriate conditions and assumptions needed to calculate a confidence interval around the population mean of amount of money spent at the supermarket.

 Include an appropriate graph to support your answer.

(c) The researcher knows that the population average amount of money spent by an adult at the supermarket in the last 30 days is $480. She believes that men, on average, spend less than this amount. Is there evidence to support this claim, based on this sample? In performing this test:

i. State appropriate hypotheses (define any symbols used).

ii. Using an appropriate formula and showing all working, calculate the value of a suitable test statistic for this test.

iii. Without using SPSS, calculate the P-value of this test.

iv. Interpret the P value and write a meaningful conclusion at the 1% level of significance.

(d) Check your answers for part (c) by finding the value of the test statistic and the P-value using SPSS. Include SPSS output in your answer and comment on the comparison with the hand calculated values. Explain any differences.

Assignment-Data-Set