4 & 5. Statistics, Quality Assurance and Calibration Methods
Hypothesis Testing (t-Test)
Multiple Choice
The average height of the US male is approximately 68 inches. What is the probability of selecting a group of males with average height of 72 inches or greater with a standard deviation of 5 inches?
A
84.61 %
B
78.81 %
C
84.85 %
D
79.10 %
Verified step by step guidance1
Identify the given values: the mean (μ) is 68 inches, the standard deviation (σ) is 5 inches, and the sample mean (x̄) is 72 inches.
Calculate the z-score using the formula: z = (x̄ - μ) / σ. Substitute the given values into the formula to find the z-score.
Use the z-score to find the corresponding probability from the z-table. The z-table provides the probability that a value is less than the given z-score.
Since the problem asks for the probability of selecting a group with an average height of 72 inches or greater, subtract the z-table probability from 1 to find the probability of being greater than the z-score.
Compare the calculated probability with the given options to determine which one is closest to the calculated value.
