A sample survey by Nielsen Media Research looked at computer access and use of the Internet. Whites were significantly more likely than blacks to own a home computer, but the black-white difference in computer access at work was not significant. The study team then looked separately at the households with at least $40,000 income. The sample contained 1924 white and 126 black households in this class. Here are the sample counts for these households. Blacks Whites Own home computer 84 1180 Computer access at work 104 1135 (a) Do higher-income blacks and whites differ significantly at the 5% level in the proportion who own home computers? Z = -1.80 X X P-value = 0.96 Conclusion There is significant evidence that the proportion of higher-income blacks and whites that own home computers differs. There is no evidence that the proportion of higher-income blacks and whites that own home computers differs. (b) Do they differ significantly at the 5% level in the proportion who have computer access at work? Z = -1.045986135 X X P-value = 0.8522162602 Conclusion There is significant evidence that the proportion of higher-income blacks and whites that have computer access at work differs. There is no evidence that the proportion of higher-income blacks and whites that have computer access at work differs