Question

Assume that adults were randomly selected for a poll. They were asked if they "favoror oppose using federal tax dollars to fund medical research using stem cells obtained from human embryos."Of those polled,490were in favor,396were opposed,and 123were unsure. A politician claims that people don'treally understand the stem cell issue and their responses to such questions are random responses equivalent to a coin toss. Exclude the 123subjects who said that they were unsure,and use a 0.05

significance level to test the claim that the proportion of subjects who respond in favor is equal to

0.50.

What does the result suggest about the politicians claim?

The test statistic for this hypothesis test is?

The P-value for this hypothesis test is ?

Use the conclusion from the previous step to think about whether or not the statement made by the politician is accurate.

Please include calculation; I keep getting something wrong when calculating the test statistic.

Answer 1

After exclude the 123subjects who said that they were unsure, we have sample size of 490+396= 886

sample proportion for favor p(hat) = (490/886) = 0.553

population proportion po = 0.50

Null hypothesis :- proportion is equal to 0.50

Alternate hypothesis:_ proportion is not equal to 0.50  

z test statistics =

using z distribution table for left tailed hypothesis, check 3.1 in the left most column and 0.06 in the top row, then select the intersecting cell and take double value (p value for two tailed is double of p value of one tailed hypothesis)

p value = 0.0016

it is clear that the p value is less than 0.05 significance level, rejecting the null hypothesis as result is significant

Therefore, politician's statement is incorrect because we are rejecting the null hypothesis.

We can say that at 0.05 significance level, there is sufficient evidence to warrant the rejection of politician's claim.