Answer:
The probability that the sample mean would be greater than 77.21 WPM = 0.9945
Step-by-step explanation:
Mean number of Words per Minute = u = 81
Standard Deviation = s = 17
sample size = n = 130
Target value = x = 77.21
we can find the probability by converting x to z-score.
The formula for z-score = [tex]\frac{x-u}{\frac{s}{\sqrt{n} } }[/tex]
using given values, z-score = [tex]\frac{77.21-81}{\frac{17}{\sqrt{130} } }[/tex]
=> -2.54
using the z table, we can find the find the probability of -2.54, that is 0.9945.
Therefore, the probability that the sample mean would be greater than 77.21 WPM = 0.9945
