Binomial and Normal Distribution Review

Which is NOT true about the standard normal distribution?

• It is bell-shaped.
• It is unimodal.
• The mean is 0 and the standard deviation is 1.
• It is asymmetrical.

If I tell you that you scored at the 55th percentile on your final exam, you would know:

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

• You earned a 55% on the exam

• You failed the exam

• 45% of the class scored worse than you did

The 75th percentile is also know as the

• median
• third quartile
• 1st quartile`
• interquartile range

What is the the total area under the standard normal distribution curve?

• 100
• 25
• .5
• 1

The 40 yards sprint times for a soccer team are found to be normally distributed with a mean of 5.2 seconds and a standard deviation of 0.3 seconds.  What is the z-score for a player who runs a time of 5.6 seconds?

• -1.33
• 1.33
• 0.88
• 1.02

The shelf life of a particular dairy product is normally distributed with a mean of 12 days and a standard deviation of 3 days.

About what percent of the products last between 12 and 15 days?

• 68%
• 34%
• 16%
• 2.5%

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%

If the value we are looking for is the same as the mean, the value of z is:

• Not enough information

• Positive

• Negative

• 0

μ = 70 , σ = 8 , X = 50 . Find z score

• 2.5
• -2.5
• 5.2
• -5.2