Normal Curves Grade Recovery

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

• 100
• 25
• .5
• 1

Tags

CCSS.7.SP.C.7A

The 40 yards sprint times for a soccer team are found to be normally distributed with a mean of 5.2 seconds and a standard deviation of 0.3 seconds. What is the z-score for a player who runs a time of 5.6 seconds?

• -1.33

• 1.33

• 0.88

• 1.02

Answer explanation

$z=\frac{5.6-5.2}{0.3}$ you must be able to show your work

Tags

CCSS.HSS.ID.A.4

The shelf life of a particular dairy product is normally distributed with a mean of 12 days and a standard deviation of 3 days.

About what percent of the products last between 12 and 15 days?

• 68%

• 34%

• 16%

• 2.5%

Answer explanation

normalcdf(12,15,12,3) must identify mean =12 sd=3 lower bound=12 upper bound =15

you could also just look at the empirical rule for sd and realize it's 34%

Tags

CCSS.HSS.ID.A.4

The heights of male students are Normally distributed with mean 1.7 m and standard deviation 0.2 m

In a population of 400 male students, how many would you expect to have a height between 1.4 m and 1.6 m?

• 24

• 54

• 97

• 100

Answer explanation

first you need to find the area under the curve between the 2 points (percent) then multiply by the sample of 400

invnorm(1.4,1.6,1.7,.2)=.241730375

.2430375*400=96.69 therefore 97

Tags

CCSS.HSS.ID.A.4

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

• 34%

• 84%

• 95%

• 68%

Answer explanation

normalcdf lb:68 ub: 200 mean:75, sd:7

Tags

CCSS.HSS.ID.A.4

If the value we are looking for is the same as the mean, the value of z is:

• Not enough information

• Positive

• Negative

• 0

Tags

CCSS.HSS.ID.A.4

Z-score of 2.5 on an IQ test is considered a genius (mean=100, SD=16). What score makes someone a genius? Hint: SOLVE for X )

• 89.2

• 130

• 99.38

• 140

Answer explanation

$\frac{x-100}{16}=2.5,\ x=140$

Tags

CCSS.HSS.ID.A.4

True or False:

The mean of the sample means is equal to the mean of the population.

• True

• False

Tags

CCSS.6.SP.A.2

This data is normally distributed.  What percentage of the data is in the shaded region?

• 68%
• 34%
• 17%
• 50%

Tags

CCSS.HSS.ID.A.4

This data is normally distributed.  What percent of the data is in the shaded region?

• 5%
• 95%
• 2.5%
• 50%

Tags

CCSS.HSS.ID.A.4