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:
Answer:
Don't worry Its a
Step-by-step explanation:
Answer:
Not sure if this is correct but I hope this helps :)
Answer:the original price is $680
Step-by-step explanation:
1/4(x)=170
4×1/4(x)=4×170
x=$680
The answer would be 40% :)