Question

MORE BENEFITS OF EATING ORGANIC

Using data from a study, we find a significant difference in the proportion of fruit flies surviving after 13 days between those eating organic potatoes and those eating conventional (not organic) potatoes. This exercise asks you to conduct a hypothesis test using additional data from this study.¹ In this case, we are testing

H0:po=pcHa:po>pc

where po and pc represent the proportion of fruit flies alive at the end of the given time frame of those eating organic food and those eating conventional food, respectively. We have n1=n2=500. Show all remaining details in the test, using a 5% significance level.

Effect of Organic Raisins After 20 Days

After 20 days, 275 of the 500 fruit flies eating organic raisins are still alive, while 170 of the 500 eating conventional raisins are still alive.


¹Proportions approximated from information given in the paper.

Give the test statistic and the p-value.

Round your answers to three decimal places.

Test statistic = Enter your answer; test statistic

p-value =

Answer 1

Let denote the proportions of fruit flies eating organic raisins are still alive and eating conventional raisins are still alive respectively.