Normal Probabilities

Normal Probabilities

Multiple Choice

If the mean number of words typed is 40 with a standard deviation of 7, what percentage of people type more than 26 words per minute?

• 2.5%

• 13.5%

• 84%

• 95%

• 97.5%

Multiple Choice

If the mean number of words typed is 40 with a standard deviation of 7, what percentage of people type less than 47 words per minute?

• 2.5%

• 13.5%

• 84%

• 95%

• 97.5%

Multiple Choice

If the mean number of words typed is 40 with a standard deviation of 7, between what number of words type do 95% of all people type

• 19 - 61 words

• 26 - 54 words

• 33 - 47 words

• 47 - 61 words

• 19 - 54 words

Open Ended

Will Rachel's Z-score be positive, negative, or zero? Explain your answer.

Open Ended

Explain what Rachel's Z-score of Z = 1.71 mean in context of this scenario.

Multiple Choice

Which curve below represents the percentage of people who typed more words than Rachel in a minute?

Multiple Choice

Find the value for

P(Z > 1.78)

• 0.0376

• 0.0375

• 0.0446

• 0.2420

Multiple Choice

Find the value for 
P(Z < -0.39)

• 0.3498
• 0.3483
• 0.3501
• 0.6502

Multiple Choice

Fernando is 60 inches tall. The average height for his age and gender is 68 with a standard deviation of 10 inches. Assuming height follows a Normal distribution, what percent of his peers are shorter than him?

• 46.81%

• 8%

• 78.81%

• 21.19%