Question 2

Solution 2:
Consider the given information,
Claim value of use of cell phones during trips,
Sample size,
Classmates report mean,
Standard deviation,
(a)
Null hypothesis:
(b)
Directional and non-directional alternative hypothesis:
(c)
Here, we have to check that use of cell phone is significantly less than the general population that is 0.60. thus, directional alternative hypothesis is good for this test.
(d)
The test-statistic is given as follows:

(e)
The p-value of the test is given as follows:
p-value

Here, p-value is greater than the level of significance 0.05 (assumed). Thus, we failed to reject the null hypothesis.
(f)
Type-1 error:
Type-2 error:
(g)
The descriptive statistics are,
mean
standard deviation
sample size
here, for one tailed proportion...