Question

1.) If a z-score is larger than _________ it is considered extreme.

a. +/- 2

b. +/- 0.05

c. +/- 1.64

d. +/- 1.25

2.) For a population with µ = 200 and σ = 25, the distribution of sample means (based on samples of size n = 25) will have a mean of _______ and a standard error of _______.

3.) A normal distribution has μ = 70 and σ = 10.   What is the probability of randomly selecting a score greater than 80 from this distribution?

4.) A normal distribution has a mean of µ = 60 with σ = 5.   If one score is randomly selected from this distribution, what is the probability that the score will be less than X = 58?

5.) For a normal distribution, the proportion located between z = –1.00 and z = 0 is ?

Answer 1

1) If a z-score is larger than +/- 2 it is considered extreme.

2) For a population with µ = 200 and σ = 25, the distribution of sample means (based on samples of size n = 25) will have a mean of 200 and a standard error of =25/sqrt(25)=5

3)

A normal distribution has μ = 70 and σ = 10.   What is the probability of randomly selecting a score greater than 80 from this distribution =P(Z>(80-70)/10)=P(Z>1)=0.1587

4)

probability that the score will be less than X = 58=P(Z<(58-60)/5)=P(Z<-0.4)=0.3446

5)

proportion located between z = –1.00 and z = 0 is =0.3413