1) A doctor wishes to know if coffee consumption by coffee drinkers has changed in the last year. She surveys 400 patients from her practice who are known coffee drinkers. She found that 312 patients...

1) A doctor wishes to know if coffee consumption by coffee drinkers has changed in the last year. She surveys 400 patients from her practice who are known coffee drinkers. She found that 312 patients drink more than 2 cups of coffee per day. The rest of the respondents drink only 1 – 2 cups of coffee per day. The doctor’s previous research found that 75% of coffee drinkers drink more than 2 cups of coffee per day.

a)  What are the null and alternative hypotheses for this study? Is this a one-tailed or a two-tailed test?

b)  What test should the doctor use to test her hypothesis? Justify your answer.

c)  Based in your answers to Parts A and B above, calculate your appropriate test statistic.

d)  Assume that the doctor set α to 0.05 during the design phase of her study.

-Calculate the degrees of freedom.

- State final conclusion for this study based on α and the degrees of freedom.