In: Statistics and Probability
A study claims 32% of U.S. adults eat chocolate daily. A researcher suspects the actual percentage is greater than this. The researcher randomly selects 88 people and finds 39 of them eat chocolate daily. Perform a hypothesis test using ∝ = 0.05. Step #1: State the null and alternative hypothesis. Identify the claim.Step#2: Find the test value.Which test is needed?Right,left, or two tailed Step #3: Find the p-value. Do not reject or reject the null hypothesis?
Solution :
Given that,
= 0.32
1 - = 0.68
n = 88
x = 39
Level of significance = = 0.05
Point estimate = sample proportion = = x / n = 0.44
This a right (One) tailed test.
Step #1:
The null and alternative hypothesis is,
Ho: p = 0.32
Ha: p 0.32
Step #2:
Test statistics
z = ( - ) / *(1-) / n
= ( 0.44 - 0.32) / (0.32*0.68) /88
= 2.413
The null and alternative hypothesis is,
Step #3:
P-value = P(Z > z )
= 1 - P(Z < 2.413 )
= 1 - 0.9921
= 0.0079
The p-value is p = 0.0079, and since p = 0.0079 < 0.05, it is concluded that the null hypothesis is rejected.
Step #4:
Reject the null hypothesis.