Normal Distributions

Front

What does the z-score represent?

Back

The amount of standard deviations a data value is above or below the mean.

Front

If you scored at the 55th percentile on your final exam, what does it mean?

Back

55% of the class scored the same or worse than you did.

Front

What is the mean (μ) and standard deviation (σ) for modern IQ scores?

Back

μ = 100, σ = 15.

Front

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

Back

130.75.

Front

What is the mean and standard deviation of male long jumpers at State College?

Back

Mean = 263 inches, Standard Deviation = 14 inches.

Front

If a male long jumper's jump ranked in the 75th percentile, how long was his jump?

Back

272.44 inches.

Front

What is the mean number of accidents per week at a company?

Back

6.4 accidents.

Front

What is the standard deviation of accidents per week at a company?

Back

1.5 accidents.

Front

What proportion of weeks would you expect to have more than 7 accidents?

Back

0.3446.

Front

What is the formula for calculating a z-score?

Back

z = (X - μ) / σ, where X is the value, μ is the mean, and σ is the standard deviation.