Answer:
a) t = 2.8982
b) 1.826
Step-by-step explanation:
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 18 - 1 = 17
99% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 17 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.99}{2} = 0.995([tex]t_{.995}[/tex]). So we have T = 2.8982. This is the answer for a.
The margin of error is:
M = T*s = 2.8982*0.63 = 1.826
In which s is the standard deviation of the sample.
