We cannot calculate the confidence interval without the sample size. However, for the second question, the sample size needed would be 49.
The formula we use is

To find the z-score:
Convert 98% to a decimal: 0.98
Subtract from 1: 1-0.98 = 0.02
Divide by 2: 0.02/2 = 0.01
Subtract from 1: 1-0.01 = 0.99
Using a z-table (http://www.z-table.com) we see that this value is closest to a z-score of 2.33.
Using the z-score, our standard deviation (9) and our margin of error (3), we have:
$12.48/6= $2.08
$14.42/7= $2.06
$10.35/5= $2.07
So you are looking for the best deal.
The best deal would be:
B.) 7 bottles for $10.35
Hope that helps!!
Have a wonderful day!!
Answer:
Number of boxes Trisha pack = 18 boxes
Step-by-step explanation:
Given:
Number of boxes Trisha pack = X
Number of bottles in each box = 12
Total number of bottle = 216
Find:
Number of boxes Trisha pack
Computation:
Total number of bottle = Number of boxes Trisha pack x Number of bottles in each box
216 = X × 12
X = 216 / 12
X = 18
Number of boxes Trisha pack = 18 boxes