5.3 - Inverse Normal Distributions

Front

What is the mean (μ) and standard deviation (σ) of a normal distribution for IQ scores?

Back

Mean (μ) = 100, Standard Deviation (σ) = 15.

Front

What IQ score qualifies one to be a member of Mensa (top 2%)?

Back

An IQ score of 131 or higher qualifies one to be a member of Mensa.

Front

What is the significance of the top 5% in the context of GRE scores for Hobby Lobby University?

Back

Students must score in the top 5% to be accepted, which corresponds to a GRE score of 166 or higher.

Front

How do you find the z-score for a given area under the normal distribution?

Back

Use a z-table or statistical software to find the z-score corresponding to the desired area.

Front

What is the z-score for an area of 0.4364 to its left?

Back

The z-score is -0.16.

Front

What is the mean height and standard deviation for men aged 20-29 in the U.S.?

Back

Mean height = 69.6 inches, Standard Deviation = 3.0 inches.

Front

How do you determine the minimum height in the top 17.5% of a normal distribution?

Back

Find the z-score corresponding to 0.825 (1 - 0.175) and use the formula: X = μ + zσ.

Front

What is the minimum height for the top 17.5% of men aged 20-29?

Back

The minimum height is 72.40 inches.

Front

What is the mean distance and standard deviation of John Daly's golf drives?

Back

Mean distance = 315 yards, Standard Deviation = 12 yards.

Front

How do you find the lengths of drives that constitute the middle 60% of John Daly's drives?

Back

Calculate the z-scores for the 20th and 80th percentiles and use the formula: X = μ + zσ.