Question

2. Dean and Cas are arguing about which is better: cake or pie. They decide to conduct a survey to see which of the two people prefer. (a) (4pts) What population parameter are Dean and Cas interested in? Describe this with a complete sentence and with appropriate notation. (b) (4pts) Dean and Cas go to several diners around America and find that of the 400 people they asked, 125 preferred pie. Is 125 400 a parameter or a sample statistic? (c) (4pts) What is the best estimate for the population parameter? What do I need to do to calculate the population parameter exactly?

3. (6 pts) In troubling times, I turn to chocolate to keep life on track. I think I need at least 150g of chocolate daily. If I’m eating less than this, I need to adjust my chocolate habit to eat more. I keep track of my chocolate consumption for 25 days and find I eat an average of 125 grams each day and s = 50g. Conduct a formal hypothesis test, using a formula to find t and SE. Figure 1 will give you the information for the p-value.

4. (2 pt each) TRUE or FALSE:

(a) The population parameter I should use one categorical variable is ˆp. (T / F)

(b) Randomization distributions are centered at the original sample statistic. (T / F)

(c) There is a 95% probability the population parameter is within a specific 95% confidence interval. (T/F)

(d) If the correlation is strong and positive, we can claim causation. (T/ F)

Answer 1

2)a)Lets say p be the proportion who prefer pie

Population parameter Interested=p

b)p=125/400 is a sample statistic

c)Best estimate for population=125/400=0.3125

d)We have to increase the sample size if we want to reduce the error

3)H0:u>=150, Ha:u<150

Assuming a pvalue of 5%. we have critical value=2. Hence, we reject H0 and conclude the person is eating less than 150gm per day

4)a)False

b)True

c)False

d)True

d)