Chapter 5 Checkpoint

Find the Z-score.

Mean = 22

Standard Deviation: 3.1

x = 29

• 2.26

• 16.45

• -2.26

• 1.26

Tags

CCSS.HSS.ID.A.4

Find the mean

Z-score = -0.4

Standard Deviation: 7

x = 20

• 22.8

• 17.2

• 22.04

• 32.5

Tags

CCSS.HSS.ID.A.4

CCSS.HSS.MD.A.2

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

Tags

CCSS.HSS.ID.A.4

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 z-score for a temperature of 17 degrees?  

• 1 
• 1.43
• -1.43
• 11.5

Tags

CCSS.HSS.ID.A.4

Which of these could be a cumulative frequency graph?

• 
• 

Tags

CCSS.6.SP.A.2

CCSS.6.SP.B.4

How many pairs of shoes does a typical teenage boy own? To find out, a group of statistics students surveyed a random sample of 20 male students from their large high school. Then they recorded the number of pairs of shoes that each boy owned. Here are the data.

14, 7, 6, 5, 12, 38, 8, 7, 10, 10, 10, 11, 4, 5, 22, 7, 5, 10, 35, 7

Martin is the student who reported owning 22 pairs of shoes. Find Martin's percentile.

• 17/20 = 0.85 or the 85th percentile

• 3/20 = 0.15 or the 15th percentile

• 10/20 = 0.50 or the 50th percentile

• There is no percentile.

What percentile is 74 in the following group of data?

35, 65, 68, 100, 23, 69, 74, 70, 61, 90, 85, 55, 30, 65, 80

• 67th

• 90th

• 75th

• 27th

The following figure is a cumulative relative frequency graph of the amount spent by a sample of 50 grocery shoppers at a store.

What is the percentile for the shopper who spent $19.50?

• $19.50 is at about the 25th percentile.

• $19.50 is at about the 75th percentile.

• $19.50 is at about the 10th percentile.

• $19.50 is at about the 30th percentile.

The following figure is a cumulative relative frequency graph of the amount spent by a sample of 50 grocery shoppers at a store.

Estimate and interpret the 80th percentile of the distribution.

• The 80th percentile is about 50. About 80% of shoppers spent less than $50.

• The 50th percentile is about 80. About 50% of shoppers spent less than $80.

• The 80th percentile is about 90. About 80% of shoppers spent less than $90.

• There is no 80th percentile.

The distribution of heights of adult American men can be modeled by a normal distribution with mean μ = 69 inches and standard deviation σ = 2.5 inches. Let X = the height (in inches) of a randomly selected adult American man. Use the 68–95–99.7 rule to approximate: P(X > 74)

• 0.025

• 0.68

• 0.95

• 0.0228