Solve the problem.
-Suppose you know that the distribution of sample proportions of fifth grade students in a large school district who read below grade level in samples of 100 students is normal with a mean of 0.30 and a standard deviation of 0.05. You select a sample of 100 fifth grade students from this district and find that the proportion who read below grade level in the sample is 0.33. How many standard deviations is the sample proportion above or below the mean of the distribution of sampling proportions?
A)6.6 standard deviation(s)above the mean
B)0.6 standard deviation(s)above the mean
C)0.57 standard deviation(s)above the mean
D)0.03 standard deviation(s)above the mean

Question

Quizplus · Accepted Answer

To find how many standard deviations the sample proportion is above or below the mean, use the formula: (sample proportion - mean) / standard deviation = (0.33 - 0.30) / 0.05 = 0.03 / 0.05 = 0.6. This means the sample proportion is 0.6 standard deviations above the mean.

Solve the Problem. -Suppose You Know That the Distribution of Sample Proportions of Sample