Probability Mixed Review

The average waist size for teenage males is 29 inches with a standard deviation of 1.4 inches. If waist sizes are normally distributed, what is the probability of teenagers who will have waist sizes greater than 31 inches?

• 0.9236

• 0.1050

• 0.1600

• 0.0764

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 probability that a randomly selected day will have a temperature of more than 17 degrees?

• 0.0062

• 0.0766

• 0.9234

• 0.9938

Alex's baby was in the 96th percentile for height when she was born. Given σ = 2 inches, and µ = 20 inches, how long was Alex's baby when she was born?

• 23.5 inches

• 20.15 inches

• 17.45 inches

• 37 inches

A ball manufacturer claims that only 15% of his balls are defective. If Ali has 6 of these balls to play with at a ball game, find the probability at most 4 balls will be defective.

• 0.9941

• 0.0059

• 0.9996

• 0.9527

Snobby University accepts only those graduate students who score in the top 5% of the GRE (Graduate Requirements Exam).

Given that µ = 151.3 and σ = 8.7, what is the lowest score you can get and still be accepted to SU? Round to the nearest whole number.

• 165

• 166

• 170

• 162

The marks obtained by the students are normally distributed with mean 61 marks and variance 100 marks. Find the probability of the students obtain at least 85 marks.

• 0.4207

• 0.0082

• 0.1112

• 0.9918

Salmi expected to receive 4 emails in a week. Find the probability of receiving 8 emails for the next 2 weeks.

• 0.0511

• 0.0297

• 0.5470

• 0.1395

A continuous random variable is normally distributed with mean 145 and standard deviation is 5. Find P(136<X<140).

• 0.8054

• 0.8772

• 0.1228

• 0.1587

A new surgical procedure is successful 85% of the time. the procedure is performed 8 times and it can be assumed that it is independent each time. Find the expected value of the successful operations.

• 1.02

• 6.8

• 0.1275

• 1.2

• 153.65

• 154.65

• 155.65

• 149.79