Download Homework due 3/9/2017

Community College of Denver
Course: MAT135 –Statistics
Instructor: Vikki French
[email protected]
PRINT YOUR NAME:
______________________________________
Homework due 3/9/2017
Reading assignment for next class: Sullivan 8.2
Introduction to Statistics Online Edition (free textbook on vf-tropi.com) p319-321
or your own book, the chapters on “Sampling Proportions”
Normal vs Non-normal Distributions
1) From which of these would you expect the distribution of sample means to be
normally-distributed if your sample size was 50?
a)
b)
c) both
d) neither
Estimating μ
Suppose we have a population of x̄s from samples of size 38
The mean of the x̄s is 63
The standard deviation is 7
2) Can we assume the population of x̄s forms a normal distribution? Why or why not?
3) What is the best estimate of the original population mean?
4) What is the best estimate of the original population standard deviation?
5) What is the standard error?
6) What will be the normal curve
for the x̄s:
_______ _______ _______
_______
_______ _______ _______
7) What is the probability that the true population mean is between 56 and 70?
8) What is the probability that the true population mean is 63?
9) What is the range of values that would ensure with 95% probability that we include the
mean?
10) What is the probability the true p lies between 55 and 65?