Stats ch 2 2014
Stats 2-2
Research Studies
Observation vs Experiment Studies
Anobservationisjustlooking.
Observational study characteristics
a. Follows a group of people
b. Target variable is studied
c. No intervention or treatment
d. Not usually randomiz
Stats ch 2 2014
Algebra 2H
Stats 2-5 Hypothesis Testing
Hypothesis tests:
Basic format:
A researcher hypothesizes their treatment (the independent variable) is affecting the results of the
experiment (the dependent variable). Their hypothesis is called th
Stats ch 2 2014
Stats 2-3
Z scores and z table
Normal Distribution
this is a continuous distribution that is symmetric, single-peaked, and bell
shaped. We can describe the distribution by giving the mean ( ) and the standard deviation ( ).
Typically 68% o
Stats ch 2 2014
Stats 2.4 Sampling distribution
In the real world, it was usually not possible to take data from an entire population. Sometimes it is
tootimeconsuming,sometimesitstooexpensiveandsometimesitisjustnotethical.Mostresearch
studies start by ta
Stats ch 2 2014
Stats chapter 2-1
SRS and the Random number table
Some ways to obtain data include:
Census
contact all the individuals
Survey
ask questions of individuals ( this may be affected by a bias)
SRS
Simple Random Sample: every individual equally
Stats ch 2 2014
Stats chapter 2-1
SRS and the Random number table
Some ways to obtain data include:
Census
contact all the individuals
Survey
ask questions of individuals ( this may be affected by a bias)
SRS
Simple Random Sample: every individual equally
Statistical Displays
Statistics is the branch of mathematics focused on the collection, analysis and
interpretation of data. From politics to sports to research labs, statistics are used in
virtually every field. During the last 20-30 years, we have seen
c. H
. \ Questions on SPUR Objectives
\ 0&5 On am 0th 1w.
SPUR stands for Skills, Properties, Uses, an Representations. The Chapter Review
questions are grouped according to the SPUR Objectives for this chapter.
SKILLS DEAL WITH THE PRO
Algebra 2H
S1.5 Worksheet
For 1-3, graph each histogram and describe its shape considering
minimum, maximum, class size, peaks, symmetry, skew, gaps, and outliers.
Give the class in which the median would be located.
1. These are the scores for the 2002 L
2
3
4. Draw box plots of both the Jan 2 and Dec 31 data.
5.
6. Use the stemplot for Jan 2.
What percentile is the number 61? _
What percentile is the number 38? _
What number is closest to the 20th percentile? _
What number is closest to the 85th percenti
Review Problems (cont.)
#2 p. 845 The probability distribution for the number of defects in a shipment of alarm clocks, based on
past data, is given below. Find the expected number of defects in a shipment of alarm clocks.
#38 p. 851 The probability distr