A grouped frequency distribution has a mean of 100 and a standard deviation of 20. The class limits for one class are 50 up to 60. Based on the normal distribution, what is the probability that an observation would be in this class?
A) 0.4938
B) 0.4772
C) 0.0166
D) -0.0166

Question

Quizplus · Accepted Answer

The probability is found by calculating the z-scores for the class limits and finding the area under the normal distribution curve between these z-scores. The z-scores are (50-100)/20 = -2.5 and (60-100)/20 = -2. The probability between these z-scores is approximately 0.0166.

A Grouped Frequency Distribution Has a Mean of 100 and a Standard