(EXCEL only)

A young investor in the stock market is concerned that investing in the stock market is actually gambling, since the chance of the stock market going up on any given day is 50%. She decides to track her favourite stock for 113 days and finds that on 43 days the stock was "up."

a) Test the appropriate hypothesis.

b) Find a 95% confidence interval for the proportion of days the stock is "up." Check the conditions.

c) What is the significance level of this test?