Normal Distribution

Given that X ~N(5, 9)

Find p(X > 9):

• 1

• .321

• .25

• .091

• .900

Students pass a test if they score 50% or more.

The marks of a large number of students were sampled and the mean and standard deviation were calculated as 42% and 8% respectively.

Assuming this data is normally distributed, what percentage of students pass the test? in percentage...

• 5

• 16

• 24

• 32

Given a mean of 75 and a standard deviation of 7, what percentage of scores are between 75 and 82?

• 68%

• 81.5%

• 16%

• 34%

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

• 34%

• 84%

• 95%

• 68%

The normal curve is symmetrical about the mean.

• True
• False

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

• 100

• 25

• .5

• 1

If 10 is added to every value in a set of data, what will happen to the value of the standard deviation?

• it will increase
• it will decrease
• it will stay the same
• it will both increase and decrease

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

Tags

CCSS.HSS.ID.A.4

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

X~N(20, 100)

What is p(X < 18)?

• 0

• .705

• .421

• .881

• .247