X=1/2 means here square root
square root 16 is 4
Answer:
Step-by-step explanation:
let the original price be x
discount is 25%, .25x
discounted price x-.25x=.75x
112.50=.75x
x=150 was the membership selling before the discount
Answer:
The sample size needed is 2401.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of , and a confidence level of , we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of .
The margin of error of the interval is:
95% confidence level
So , z is the value of Z that has a pvalue of , so .
Estimate the sample size needed if no estimate of p is available so that the confidence interval will have a margin of error of 0.02.
We have to find n, for which M = 0.02.
There is no estimate of p available, so we use
The sample size needed is 2401.