In: Statistics and Probability
4. Hypothesis testing for the population proportion. This next problem focuses on using technology to perform a hypothesis test for the true proportion of students with no credit card debt. Prior studies seemed to indicate that the true proportion of students with no credit card debt was 10%; however, new data leads a researcher to claim that the true proportion of students with no credit card debt is different than 10%. You will test this claim. Use appropriate technology with a significance level α = 5%. Identify the best estimate for the population proportion. 12 out of 100 have no credit card debt.
Sample values:
8331 |
4596 |
3617 |
3123 |
4435 |
1182 |
3235 |
1781 |
3479 |
1552 |
0 |
1432 |
7111 |
1266 |
2971 |
0 |
1099 |
1145 |
4519 |
2666 |
2284 |
1205 |
0 |
4819 |
1366 |
1213 |
1411 |
4717 |
5982 |
1276 |
3802 |
7299 |
2161 |
2225 |
1651 |
3417 |
1804 |
1230 |
2392 |
1286 |
3499 |
1564 |
0 |
2694 |
4925 |
0 |
3734 |
3350 |
1229 |
1479 |
2905 |
3685 |
0 |
6089 |
0 |
2090 |
2202 |
5430 |
6449 |
1230 |
0 |
1722 |
3916 |
3924 |
5165 |
2934 |
1561 |
4697 |
1102 |
5651 |
4818 |
7090 |
6014 |
1640 |
2425 |
3056 |
2442 |
7012 |
4344 |
6178 |
1271 |
2417 |
1261 |
3688 |
0 |
2618 |
3513 |
8339 |
1464 |
3291 |
0 |
9037 |
3904 |
1198 |
7406 |
1208 |
0 |
7835 |
0 |
6192 |
We have to test the claim whether the true proportion of students with no credit card debt is 10% or different, i.e. different means either less than 10% or greater than 10%
So, it is a two tailed hypothesis.
For null hypothesis, we will assume that the true proportion is unchanged and equal to 10%
For alternate hypothesis, we will test that the true proportion is changed and not equal to 10%
We have to use z proportion test in this case because we have sample proportion and population proportion.
Formula for z test statistic is given as
where
setting these values, we get
this gives us
z = 0.67
Now, we have to find p value corresponding to this z value at 0.05 level of significance.
Using z distribution for z value = 0.67 for two tailed hypothesis test. (look 0.6 in left most column and 0.07 on top most row, pick the intersection of these column and row)
we get
p value = 0.5029
It is clear that p value is greater than 0.05 level of significance. So, result is significant.
we failed to reject the null hypothesis.
So, we can conclude that there is insufficient evidence to support the claim that true proportion of students with no credit card debt is different than 10%.