Normal Distribution Review

The mean number of accidents a week at a company is 6.4 with a standard deviation of 1.5. What is the probability of 7 or more accidents this week? Assume a Normal distribution.

• 0.3446

• 0.2856

• 0.4

• 0.6554

The GPAs of students are normally distributed at UCDavis with a mean of 3.2 and a standard deviation of 0.3. What is the probability that a student selected at random has a GPA between 2.9 and 3.8?

• .8185

• .4772

• .1359

• .8216

If the mean of a data set is 18 and the standard deviation is 3. What original data value has a z-score of -1.2?

• 21.6
• 16.8
• 14.4
• 21

Tags

CCSS.HSS.ID.A.4

The weights of miniature horses are roughly normally distributed with a mean of 230 pounds and standard deviation of 45 pounds.

What is the probability that a miniature horse randomly selected weighs less than 140 pounds?

• .4772

• .0228

• .9544

• .0456

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?

• Approx. 115

• Approx. 131

• Approx. 145

• Approx. 120

Find the value for 
P(Z > 1.78)

• 0.0376
• 0.0375
• 0.0446
• 0.2420

Tags

CCSS.HSS.ID.A.4

Find the value for 
P(Z < -0.39)

• 0.3498
• 0.3483
• 0.3501
• 0.6502

Tags

CCSS.HSS.ID.A.4

Find the value for

P(Z > - 2.46)

• 0.4931

• 0.9931

• 0.007

• 0.99

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

• Approx. -0.151

• Approx. -1.711

• Approx. 1.711

• Approx. 0.151

What's the probability of x < 13 for a normal distribution ?

(Mean = 20, Standard dev = 6.5)

• 0.3529

• 0.1471

• 0.8529

• 0.6471