Chapter 9.1 and 9.2 : Testing hypotheses
about a population mean
Example1 .Suppose that a pharmaceutical
company is concerned whether the mean potency
of an antibiotic meet the minimum government
potency standards. They need to decide between
two possi

both answers will
be accepted.
Question 2
people in this city.
Question 3
No relationship between gender and happiness.( If you believe that difference is big enough show your calculations
and you will get a full credit. At this point it is subjective )
Q

Measures of central tendency (ungrouped data)
Chapter 3.1 and 3.2
Numerical descriptive measures
The mode: is the sample value that occurs most
frequently.
The median: is the value that falls in the middle
position when the sample values are ordered from

Table IV
C19
Standard Normal Distribution Table
Table IV Standard Normal Distribution Table
The entries in this table give the
cumulative area under the standard
normal curve to the left of z with the
values of z equal to 0 or negative.
z
z
z
0
.00
.01
.0

Hw2 additional solution
Problem 4
Problem 5 True or False
a) If the correlation coefficient ,r= 1, then all the data points lie exactly on a straight line.
True
b) The correlation coefficient r is a number that indicates the direction and the strength of

Stat 240. Worksheet 4
1. Explain the meaning of: union, intersection, complements of events, mutually exclusive (disjoint or incompatible)
events
Consider the following events for one roll of a die.
Let A -an even number is observe, B- an odd number is ob

Worksheet 6
1. A company employs a total of 16 workers. The management has asked these employees to
select 2 workers who will negotiate a new contract with management.
The employees have decided to select the 2 workers randomly. How many total selections

Homework 2 additional (not on Wiley) due Monday, Feb 23 (Sec 2) and Wednesday, Feb 25 (Sec 1) (discussion classes)
Problem 1 (SSxx =Sxx, SSyy=Syy, SSxy=Sxy different notation )
Problem 2
Problem 3 The following table gives the temperatures(X) (in degrees

Question 7
Explain whether each of the following constitutes a population or a sample.
a. Pounds of bass caught by all participants in a bass fishing derby
b. Credit card debts of 100 families selected from a city
c. Number of home runs hit by all Major L

Sampling and sampling distributions.
Chapter 7
Parameters are numerical descriptive measures for
populations (fixed, often unknown values)
For instance: For the normal distribution: the
parameters are location and shape , described by
and .
For the binom

Worksheet CI continue solution
1.
2.
3.
You can just argue , that the sample is small comparing to the population size some book give 10% , some 5% ondition,
The same to check if your sample size is large enough to approximate by normal distribution wheth

Stat 240 - Worksheet - Condence interval for a population mean.
Question 1
A bank manager wants to know the mean amount of mortgage paid per month by homeowners in an area. A
random sample of 120 homeowners selected from this area showed that they pay an

Worksheet 7 - solutions
Problem 3
Problem 4
X- number of frogs with this trait in the sample
X~ Binomial (n=13, p=0.10)
Conditions: 1. We have n=13 , indetical trials, n-fixed
2. Each trial (frog ) two possibilities - A frog has this trait (Success), Does

Hw11 solution
We have to assume:
random sample random selection and independence, sample small comparing to the population size,
population standard deviation is given, sample large, we dont have to assume normality
Problem 3. Like always check first assu

Guillaume Pagnier
Stats 501 i
M90
Project Report
Kc.
The Relationship Between Perception of Financial Risk and Gender
Evaluating risk is a necessary aspect of our lives. To maximize our own utility, we
frequently analyze social risk situations (to avoid s

Chapter
5
Discrete Random
Variables and Their
Probability Distributions
Mean and Standard Deviation of a Discrete Random Variable
Computing the mean and standard deviation of a discrete random variable is slightly different
than computing the mean and sta

Table V
The t Distribution Table
Table V The t Distribution Table
The entries in this table give the critical values
of t for the specified number of degrees
of freedom and areas in the right tail.
0
t
Area in the Right Tail Under the t Distribution Curve

Data Analysis Project
SPRING 2015
Data Analysis Project:
brainstorm a question of interest to investigate (it can be silly the idea is to have fun
practicing statistics!)
design your own study/experiment based on that question of interest
collect data by

Chapter (8.1-8.2 )
Confidence interval for a population
mean.
Statistical inference-drawing conclusions about population
parameters from an analysis of the sample data.
Types of inference:
1. estimation of parameter(s) -obtain an estimate of the unknown
t

Homework 13 not to hand in
9.106 In a 2005 Energy Information Administration report
(http:/www.eia.doe.gov/emeu/reps/enduse/er01_us.html), the average U.S. household uses 10,654 kilowatthours of electricity per year. A random sample of 85 houses built in

Homework 12 due Thursday, April 24
8.82On November 15, 2006, carefair.com reported that 40% of women aged 30 years and older would rather get
Botox injections than spend a week in Paris. The survey consisted of 175 women in the specified age group.
a. Wha

Christine Bierema and Lisa Walker
Intro Stats
May 13, 2013
Project
Introduction
We looked at the sodium levels in cereals from two different corporations, Kelloggs and
General Mills. Sodium levels are important because too much sodium in a diet can lead t

Stat 240 Worksheet 5 solutions
Problem 1 The following table gives the twoway classification of 500 students based on sex and whether or not they
suffer from math anxiety.
Suffering from math anxiety
Yes (A)
No (NA)
Male (M)
160
80
Female (F)
175
85
a) Ar