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Elements of Stat 1 Benchmark 6 Normal Dist & CLT

Last updated about 4 years ago
27 questions
4

Explain what a z-score is and why we use it. (*use the z-score of 1.32 to help you explain)

For #2-9, Use the Standard Normal Table to find the indicated area under the standard normal curve.
3

to the left of z = - 0.84

3

to the left of z = 2.55

3

to the left of z = - 0.27

3

to the right of z = 1.68

3

to the right of z = - 0.83

3

between z = -1.22 and z = -0.43

3

between z = - 1.64 and the mean

3

to the left of z = 0.12 and to the right of z = 1.72

For #10-12, Find the indicated probabilities.
3

P (z < 1.28) =

3

P (z > - 0.74) =

3

P (- 2.15 < z < 1.55) =

For #13-15, Use the problem below:
A study found that the mean migration distance of the green turtle was 2200 kilometers and the standard deviation was 625 kilometers. Assuming that the distances are normally distributed, find the probability that a randomly-selected green turtle migrate a distance of
3

less than 1900 km

3

between 2000 km and 2500 km

3

greater than 2450 km

For #16-20, Use the Standard Normal Table to find the z-score that corresponds to the given cumulative area or percentile. If the area is not in the table, use the entry closest to the area.
2

0.4721

2

0.1

2

0.8708

2

P 2

2

P 85

For #21-25, Use the problem below:
Use the following information. On a dry surface, the braking distance (in meters) of a Pontiac Grand Am can be approximated by a normal distribution where the mean = 45.1 meters and the standard deviation =0.5 meters.
4

Find the braking distance of the car that corresponds to z = -2.4.

4

Find the braking distance of the car that corresponds to z = 1.2.

4

Find the braking distance of the car that represents the 92nd percentile.

4

Find the braking distance of the car that represents the 1st quartile.

4

What is the shortest braking distance of the Pontiac Grand and that can be in the top 10% of braking distances?

For #26 and #27 Use the information below:
The mean annual salary for chauffeurs is $30,800 and the Standard deviation is $5600. The random sample of size 45 is drawn from this population. What is the probability that the mean annual salary is
5

What is the probability that the mean annual salary is less than $30,000?

5

What is the probability that the mean annual salary is more than $34,000?