Standard Normal Probabilities

Find the z-score such that 44% of the standard normal curve lies to the right of z. 

• -0.15

• -1.71

• 1.71

• 0.15

μ = 350 , σ = 20 , find P(X > 400)

• 0.0062

• 0.9938

• 0.4013

• 0.5987

Fernando is 60 inches tall. The average height for his age and gender is 68 with a standard deviation of 10 inches. What percent of his peers are shorter than him?

• 46.81%

• 8%

• 78.81%

• 21.19%

The mean GPA of students in a course at UCDavis is 3.2 with a standard deviation of 0.3. What percent of students in the course have a GPA between 2.9 and 3.8? 

• 81.85%

• 47.5%

• 68%

• 95%

The mean temperature in Glens Falls for the month of February is 23 degrees with a standard deviation of 4.2 degrees.  What is the z-score for a temperature of 17 degrees?  

• 1 

• 1.43

• -1.43

• 11.5

The scoring of modern IQ is such that Intelligence Quotients (IQs) have a normal distribution of μ= 100 and 𝞂 = 15.

Mensa International is a non-profit organization that accepts only people with IQ score within the top 2%. What level of IQ qualifies one to be a member of Mensa?

• 115

• 130.75

• 145

• 120

According to the empirical rule, what percentage of data falls within 1 standard deviation? 

• 25%

• 68%

• 95%

• 99.7%

According to the empirical rule, how much of the data falls within 3 standard deviations? 

• 25%

• 68%

• 95%

• 99.7%

The mean number of accidents a week at a company is 6.4 with a standard deviation of 1.5.  What proportion of weeks would you expect to have less than 5 accidents?

• 0.6915

• 0.1762

• 0.8238

• -0.93

The mean number of accidents a week at a company is 6.4 with a standard deviation of 1.5.  What proportion of weeks would you expect to have more than 7 accidents?

• 0.3446

• 0.2856

• 0.4

• 0.6554