Finding Normal Distribution Probability

Assume that blood pressure readings are normally distributed with μ = 120 and σ = 8. A blood pressure

reading of 145 or more may require medical attention. What percent of people have a blood pressure reading

greater than 145?

• 0.09 %

• 99.91 %

• 6.06 %

• 11.09 %

The weights of adult male beagles are normally distributed, with a mean of 25 pounds and a standard deviation of 3 pounds. A beagle is randomly selected. Find the probability that the beagle’s weight is less than 24 pounds.

• 0.3694

• 0.3781

• 0.0912

The test scores for the exam in statistics class have a mean of 78 points and standard deviation of 9 points. A student is randomly selected. Assuming the scores are normally distributed find the probability that the score is more than 95. 

• 0.0295

• 0.00000005

• 0.3209

• 4.32

μ = 350 , σ = 20 , find P(X > 400)

• 0.0062

• 0.9938

• 0.4013

• 0.5987

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%

Find the area below a z-score of 1.25. 

• 0.89

• 0.01

• 0.79

• 0.12

Find the area under the normal distribution curve between a z=-1.26 and z=.57. 

• 0.0047

• 0.9204

• 0.6119

• 0.4981

What shape is a normal distribution curve?

• Half curve

• Round curve

• Bell curve

• Square curve

If heights of 3rd graders follow a normal distribution with a mean of 52 inches and a standard deviation of 2.5 inches, what is the z score of a 3rd grader who is 47 inches tall?

• -5

• -2

• 2

• 5

If X follows a Normal Distribution, P ( X < 25 ) =

(Hint: page 3 of notes)