Question

A national survey of 47,000 American households in 2006 found that 32.4% of the households included a pet cat. No information was provided about how the sample households were selected.

Who are the subjects?

what is the variable?

Is the variable quantitative or categorical?

If the standard deviation of the null distribution is 0.011, what is the 95% confidence interval using the 2SD method? Based on the confidence interval you found, do you believe that over one-third of American households have a cat? Explain your reasoning.

Answer 1

Who are the subjects?

47,000 American households

what is the variable?

percentage of households included a pet cat.

Is the variable quantitative or categorical?

variable is quantitative as we are measuring

If the standard deviation of the null distribution is 0.011, what is the 95% confidence interval using the 2SD method?

mean-2 sd,mean+2sd

0.324-2*0.011,0.324+2*0.011

0.302,0.346

95% mean lower limit=0.302

95% upper limit=0.346

since 1/3=0.3333333 is in the interval

There is no sufficient evidence by 95% confidence interval to believe that

over one-third of American households have a cat