Add an intersection the red light times normally distributed by the mean of three minutes and a standard deviation of .25 minute
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Answer:
There is enough evidence to support the claim that there is significant difference in the proportion of users under age 50 and users age 50 years and older that accessed the news on their cellphones (P-value=0.0000014).
Step-by-step explanation:
This is a hypothesis test for the difference between proportions.
The claim is that there is significant difference in the proportion of users under age 50 and users age 50 years and older that accessed the news on their cellphones.
Then, the null and alternative hypothesis are:
The significance level is 0.05.
The sample 1, of size n1=1100 has a proportion of p1=0.26.
The sample 2, of size n2=900 has a proportion of p2=0.17.
The difference between proportions is (p1-p2)=0.09.
The pooled proportion, needed to calculate the standard error, is:
The estimated standard error of the difference between means is computed using the formula:
Then, we can calculate the z-statistic as:
This test is a two-tailed test, so the P-value for this test is calculated as (using a z-table):
As the P-value (0.0000014) is smaller than the significance level (0.05), the effect is significant.
The null hypothesis is rejected.
There is enough evidence to support the claim that there is significant difference in the proportion of users under age 50 and users age 50 years and older that accessed the news on their cellphones.