Download Chapter 7 Study Guide: Integrated Geometry 01. Name the types of

Chapter 7 Study Guide: Integrated Geometry
01. Name the types of sampling and give an example of each. Explain what defines each type of
sampling, for example: Systematic is when a “rule” is used to determine who will be surveyed, i.e.,
every 50th person on a list.
a) self-selected – those surveyed “volunteer” to answer (online survey)
b) convenience – pick a survey group based on ease (my 5th period class)
c) systematic – a rule is used (every 50th person on list)
d) random – every member of population has equal chance of being chosen (list of every student in
school, all names placed in hat and drawn out randomly)
02. Given the graph below, determine the mean and the median.
Your x-axis values go into L1, your y-axis values go into L2. So, put the values: 5, 15, 25, 35, and 45 into
L1 and 1, 3, 6, 4, and 2 into L2. Hit 2nd function key, data, STATS 1: -Var Stats, Data=L1, FRQ=L2 CALC and
it will give you the mean (2: X =26.875 and 4:med=25) and median.
03. What are the formulas for margin of error and for determining sample size?
Margin of error =
1
1
where n is the number of people and sample size =
(m arg in _ of _ error %) 2
n
04. In a recent survey, 2750 people were surveyed to determine which satellite TV business was the
most preferred. If 39% of the people said Dish TV, what was the margin of error?
1
=
n
1
= .01906 and move the decimal 2 places right = 1.9%
2750
05. Using the results from question #04, find the interval that represents the true population of people
who prefer Dish TV. 39% + 1.9% and 39% - 1.9% = 37.1% - 40.9%
06. Define: margin of error, bias, sample size, parameter, and statistic
See definitions in your textbook!
07. What is the formula for finding the z-score?
z-score =
x X

08. Find the mean and standard deviation of the following data: 25, 26, 28, 28, 31, 34, 37, 38, 39, 42
25+26+28+28+31+34+37+38+39+42/10 = 32.8 = mean
Plug all values into L1 of calculator. STATS1: 1-Var Stats, ENTER, L1 and ONE, ENTER,  =5.7
09. If the data in #08 represents Sample A, compare it to the population’s mean, standard deviation, and
variability if the population parameters are: mean = 35.7 and standard deviation=6.02
Sample A’s mean and standard deviation is less than the population. The population’s data is more
varied than Sample A’s.
10. Describe how a normally distributed histogram looks and sketch one below. (histogram, not the bell
curve)
A normally distributed histogram should be symmetric and should follow the general pattern of the bell
curve.
11. Which equation best “fits” the scatterplot below? What is the correlation coefficient (r) for the data
values?
a) y=10.73x + 6.1
b) y=49.2x + .57
c) y=.57x + 49.2
d) y=6.1x + 10.73
correlation coefficient (r) = _______r=1___________________________________________
12. Find the line of best-fit using linear regression for the following data:
Field Trips
Students
28
38
45
48
Teachers
2
3
3
4
Students’ values go in L1, Teachers’ values go in L2. Y=.08x - .08
57
4
65
5
13. Draw a scatterplot of the data below. Sketch the line of best fit. Find the slope. Using the two points
from your slope and the point-slope formula, approximate the line of best fit. Then, using the calculator,
find the line of regression and the correlation coefficient, r. y=.46x + 51.8 and r=.955
X–
40
time in
minutes
Y – test 65
scores
40
45
60
65
75
90
90
100
100
75
70
80
85
90
90
95
95
100
14. Use the median-median line method to find a line of best fit: y=1x + 12.7
Points Corinna Scored
Time
Played
(in
minutes)
18
26
30
15
25
26
22
21
13
Number
of Points
5
11
16
2
11
13
9
10
1
15. The Acme Taxi Company has noticed that taxi #001 is not getting the same MPG as the other taxis. If
the taxis’ MPG is normally distributed with a mean of 14 and a standard deviation of 3.8, draw the
normal curve and label it for the given data.
See me for the answer if you didn’t write the answer down in class today.
16. Find the probability that one of the taxis gets between 10.2 and 21.6 MPG. Find the probability that
the taxis get more than 17.8 MPG. Find the probability that the taxis get at most 10 MPG.
( P :10.2  x  21.6)  34% + 34% + 13.5% = 81.5%
( P : x  17.8)  13.5% + 2.35% + .15% = 16%
Since 10 MPG is not part of your normal bell curve, use your z-score:
10  14
 -1.05 which rounds to
3.8
a -1.1, use your z-table = .1357 or 13.57%
17. Why can a sample be biased? Explain all that apply. (Refer to your notes on the PowerPoint where
bias was first introduced.)
If any part of the population is under represented or over represented. Self-selected and convenience
samples lend themselves to more bias than systematic or random sampling.