CAN THIS PLEASE BE COMPLETED BEFORE 20-30 MINS

1.Consider a normal distribution with mean= 12. Letxbe the sample mean. Calculate

for each of the following cases:

n=9;=90;(b) (5marks)n=9;s=102;

n=16;=80;and (d) (5marks)n=16;s=71:6:

2.The family income distribution in Ottawa is unknown but has a mean of $21500 and a standard deviation of $1700.

(a) A sample of size of 200 families is to be selected and the sample meanxcalculated. Describe the sampling distribution ofxboth in terms of general shape and descriptive measures mean and variance.

(b) If the sample size was actually 60 instead of 200, how would the sampling distribution ofxbe aected? Illustrate with a graph, indicating the mean and standard deviation.

(c) What is the probability that a sample ofn= 60selected randomly from the population will have a mean equal or greater than $21300?