Question

You have a coin that you suspect is not fair (i.e., the probability of tossing a head (PH) is not equal to the probability of tossing a tail (PT) or stated in another way: PH ≠ 0.5). To test yoursuspicion, you record the results of 25 tosses of the coin. The 25 tosses result in 17 heads and 8 tails.

a) Use the results of the 25 tosses in SPSS to construct a 98% confidence interval around the probability of tossing a head (PH). Show the variable view, data view, and output screens.

b) State the statistical null and research hypotheses

c) Use SPSS to test the null hypothesis at a significance level of 1% using a one-sample t-test. Justify the decision to retain or reject the null hypothesis using the SPSS output. Show the variable view, data view, and output screens.

Answer 1

a)

b)

Hypothesis testing is a kind of statistical inference that involves asking a question, collecting data and then examining what the data tell us about how to proceed. The hypothesis to be tested is called Null hypothesis and given the symbol H_o. We test the null hypothesis against an alternative hypothesis also called research hypothesis, which is given the symbol H_a

_c)