Proctor & Gamble claims that at least half the bars of Ivory soap they produce are 99.44% pure (or more pure) as advertised. Unilever, one of Proctor & Gamble's competitors, wishes to put this claim to the test. They sample the purity of 107 bars of Ivory soap. They find that 48 of them meet the 99.44% purity advertised.

What type of test should be run?

a. z-test of a proportion

b. t-test of a mean

The alternative hypothesis indicates a

a. two-tailed test

b. right-tailed test

c. left-tailed test

Calculate the p-value. _______________

Does Unilever have sufficient evidence to reject Proctor & Gamble's claim?

• No
• Yes