Question

A public opinion survey investigated whether a majority (more than 50%) of adults supported a tax increase to help fund the local school system. A random sample of 200 adults showed that 113 of those sampled supported the tax increase.

Researchers used these results to test H0​:p=0.5 versus Ha​:p>0.5, where p is the true proportion of adults that support the tax increase. They calculated a test statistic of z≈1.84 and a corresponding P-value of approximately 0.033.
Assuming the conditions for inference were met, which of these is an appropriate conclusion?
A. At the α=0.01 significance level, they should conclude that more than 50% of adults support the tax increase.
B. At the α=0.01 significance level, they should conclude that less than 50% of adults support the tax increase.
C. At the α=0.05 significance level, they should conclude that more than 50% of adults support the tax increase.
D. At the α=0.05 significance level, they should conclude that less than 50% of adults support the tax increase.

Answer 1

Answer: At the a = 0.05 significance level, they should conclude that more than 50% of adults support the tax increase.

Explanation:

Answer 2

Answer: C. At the α=0.05 significance level, they should conclude that more than 50% of adults support the tax increase.

Explanation:

Given: Null hypothesis:
`H_0:p=0.5`

Alternative hypothesis:
`H_a: p>0.5`

p-value = 0.033

If the p-value is greater than alpha (p > . 05), then we fail to reject the null hypothesis.

If α=0.01 , then p-value > α i.e. we fail to reject the null hypothesis.

Conclusion: Exactly 50% of adults support the tax increase.

If α=0.05 then p-value < α i.e. we reject the null hypothesis.

Conclusion: more than 50% of adults support the tax increase.

Thus, Correct option: C .