Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

1 A coin is flipped a certain number of times and comes up heads 210 times, whic

ID: 3298819 • Letter: 1

Question

1 A coin is flipped a certain number of times and comes up heads 210 times, which is 52% of the time.

How many times was the coin flipped?

2. Calculate the standard deviation of the sampling distribution when n= 16 for p= 0.5, p= 0.25, and p= 0.01. What happens to the standard deviation as p gets closer to 0?

3. What has to be true about the number of successes and failures in a sample in order to use theLarge-Sample Confidence Interval for Population Proportion?

4. Suppose you want to estimate the sample size needed to obtain a confidence interval with a particularmargin of error. Why do we need to first ‘guess’ a value forp?

Explanation / Answer

1. Suppose the coin was flipped x number of times. Then,

52% of x = 210

0.52x = 210

x = 210/0.52

x = 403.85

Since the flipping of coin can't be in fraction, the answer will be 404.