Normal Distributions Area

The mean July daily rainfall in Hulu Kinta is 10 mm and the standard deviation is 1.5 mm

Assume that this data is normally distributed.
How many days in July (31 total days) would you expect the daily rainfall to be less than 8.5 mm?

• 5

• 6

• 7

• 10

Given a mean of 75 and a standard deviation of 7, what percentage of scores are greater than 68?

• 34%

• 84%

• 95%

• 68%

Find the z-score with 20% of observations falling above it.

• z=-0.84

• z=1.84

• z=-1.84

• z=0.84

Z-score of 2.5 on an IQ test is considered a genius (mean=100, SD=16). What score makes someone a genius? Hint: SOLVE for X - there was a formula in section 5.3)

• 89.2

• 130

• 99.38

• 140

Find the area under the normal distribution curve between 
z=-1.53 and z=0.

• 0.437

• 0.563

• 0.500

• 0.063

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? 

• 81.5%

• 47.5%

• 68%

• 95%

Where can we locate the mean in the normal curve?

• to the left portion

• to the right portion

• at the center

• on the z - axis

The distances male long jumpers for State College jump are approximately normal with a mean of 263 inches and a standard deviation of 14 inches. Suppose a male long jumper's jump ranked in the 75th percentile. How long was his jump?

• 0.67 inch

• 263 inches

• 272.44 inches

• 277.25 inches

The average waist size for teenage males is 29 inches with a standard deviation of 1.4 inches.

If waist sizes are normally distributed, estimate the proportion of teenagers who will have waist sizes greater than 31 inches?

• 92.4%

• 10.5%

• 16%

• 7.6%

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