Stretch Your Thinking Ann arranges her marbles in groups, with 8 marbles in each group. She writes the fraction 5/8 to show the
fraction of marbles in each group that is red. What equivalent fraction names the fraction of marbles in 6 groups that are Red? Explain.
1 answer:
You might be interested in
Answer:
We need a sample size of least 119
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 is:
95% confidence level
So , z is the value of Z that has a pvalue of
, so
.
Sample size needed
At least n, in which n is found when
We don't know the proportion, so we use , which is when we would need the largest sample size.
Rounding up
We need a sample size of least 119