10.17 Small-business telephone users were surveyed 6 months after access to carriers other than Carrier A became available for wide-area telephone service.

Of a random sample of 240 Carrier A users, 133 said they were attempting to learn more about their options, as did 201 of an independent random sample of 260 users of alternate carriers. Test, at the 1%

significance level against a two-sided alternative, the null hypothesis that the two population proportions are the same.