A researcher claims that more than 80% of American adults believe in an afterlife. You randomly select 612 adults and find that 459 of them believe in an afterlife. At the 1% significance level, can you conclude that more than 80% of adults believe in an afterlife?
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Normal approximation (i.e., Z-table test) on the Binomial Distribution.
Mean = 612 * 0.80 = 489.6
Var = 489.6 * 0.2 = 97.92
Std = sqrt(97.92) = 9.90
Z = (489.6 - 459) / 9.9 = 3.09 > 2.58
reject null hypothesis at 1% significance level.
Mean = 612 * 0.80 = 489.6
Var = 489.6 * 0.2 = 97.92
Std = sqrt(97.92) = 9.90
Z = (489.6 - 459) / 9.9 = 3.09 > 2.58
reject null hypothesis at 1% significance level.