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1. Find the z value to the right of the mean such that 85% of the total area und

ID: 2934832 • Letter: 1

Question

1. Find the z value to the right of the mean such that 85% of the total area under the standard normal distribution curve lies to the left of it?

a. 0.41

b. –0.51

c. 1.33

d. –0.22

3. Find the probability P(-0.72 < z < -0.11) using the standard normal distribution.

0.2204

0.3504

0.0900

0.7796

4. Find the mean of the distribution shown below.

1

4.94

0.25

20

5. The average diameter of sand dollars on a certain island is 3.00 centimeters with a standard deviation of 1.00 centimeters. If 9 sand dollars are chosen at random for a collection, find the probability that the average diameter of those sand dollars is more than 2.60 centimeters. Assume that the variable is normally distributed.

0.615

0.885

0.820

0.385

0.2204

0.3504

0.0900

0.7796

4. Find the mean of the distribution shown below.


1

4.94

0.25

20

5. The average diameter of sand dollars on a certain island is 3.00 centimeters with a standard deviation of 1.00 centimeters. If 9 sand dollars are chosen at random for a collection, find the probability that the average diameter of those sand dollars is more than 2.60 centimeters. Assume that the variable is normally distributed.

0.615

0.885

0.820

0.385

Explanation / Answer

1. We need to find P(Z<z)=0.85

P(0<Z<z)+0.5=0.85

P(0<Z<z)=0.85-0.5=0.35

Using standard normal table we get z=1.036