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Answer Key: Statistics & Probability
C. Misleading Graphs
7, 1.1 & 6, 2.5
Sometimes the way in which data is presented may be misleading;
when this happens, people may draw false conclusions. On the
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Answer Key: Statistics & Probability
6, 1.1
4. The chart below shows the number of ice cream cones sold at
Buddy's Ice Cream Parlor from Monday through Friday:
Monday
Tuesday
Wednesday Thursday
Frid
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Answer Key: Statistics & Probability
On Your Own
6, 1.1
1. Find the median of the data set: cfw_3, 2, 5, 7, 3, 8, 7.
2
3
3
5
7
7
8
Answer: The median is 5.
2. In 2004, seven homes were sold in the c
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Answer Key: Statistics & Probability
Now let's look at the second problem.
6, 3.5
Example: Ariel drew from a standard deck of cards and picked a king.
Without replacing the king, he drew a second ca
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Answer Key: Statistics & Probability
7, 1.1 & 6, 2.5
2. The line graph below shows the number of claims filed with the Lost
& Found from January through October.
How many fewer claims were filed in
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Answer Key: Statistics & Probability
On Your Own
7, 1.2
1. The scatter plot shows two sets of data: dollars spent on food and
dollars spent on clothes.
What conclusions can be drawn from the scatter
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Answer Key: Statistics & Probability
6, 3.3
Let's look at another example:
Example: What is the probability that the spinner will stop at red?
Notice that, while the spinner is divided into six equa
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Answer Key: Statistics & Probability
i. Conditional Probability
6, 3.1 & 6, 3.3
Now compare the last problem with this next problem:
Example: Dina tosses a penny twice. What is the probability that
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Answer Key: Statistics & Probability
On Your Own
7, 1.1
1. The vertical bar graph represents the average rainfall (as measured
in inches) in Morristown from January through June.
What is the title o
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Answer Key: Statistics & Probability
6, 3.3
Let's do another example together:
Example: When rolling a numbered cube (with the numbers 1 to 6 on
it) what is the probability of not landing on an odd
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Answer Key: Statistics & Probability
ii.
Even Number of Values
6, 1.1
If the number of values in the data set is even, order the values from
smallest to largest and then take the mean of the two mid
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Answer Key: Statistics & Probability
7. A bag contained four green balls, three red balls, and two purple
balls. Jason removed one purple ball from the bag and did not put
the ball back in the bag.
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Answer Key: Statistics & Probability
Unit 2: Statistics: Representing & Interpreting Data
Data is information. Data is often presented visually, as in tables,
graphs and charts; this allows us to ea
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ii. Conditional Probability with a Twist
6, 3.1 & 6, 3.3
Look at the following example:
Example: Julien is rolling a numbered cube with the numbers 1 to 6
on it.
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Answer Key: Statistics & Probability
No Mode
6, 1.1
It is possible to have a data set with no mode.
Example: Find the mode of this data set: cfw_6, 9, 7, 5, 4, 3, 2
Steps:
Order the values from smal
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Answer Key: Statistics & Probability
Unit Quiz: The following questions appeared on the CAHSEE:
1. The graph below represents the closing price of a share of a certain
stock for each day of the week
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Answer Key: Statistics & Probability
On Your Own
6, 3.3
1. Marla draws one card from a standard deck of cards. What is the
probability that she will draw the king of diamonds?
Note: A standard deck
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Answer Key: Statistics & Probability
ii.
Unequal Likelihood
6, 3.3
There are times when the likelihood of the occurrence of any one
event is not equal. Look at the example below.
Example: A box cont
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Answer Key: Statistics & Probability
On Your Own
7, 1.1
1. The line graph shows the changes in the federal hourly minimum
wage from October 1938 to September 1997.
The largest increase in the minimu
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Answer Key: Statistics & Probability
F. Dependent Events
6, 3.5
Two events are dependent if the outcome of the first event affects
the outcome of the second event, so that the probability is changed
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iv.
Double Line Graphs
7, 1.1
On the CAHSEE, you may be asked to interpret a double line graph.
A double line graph shows two sets of data side by side. It is of
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Answer Key: Statistics & Probability
7, 1.1
4. The following line graph shows the distribution of grades in Ms.
Grey's Art Class.
How many students received an A or a B? 14
How many more students re
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18. The number of games won over four years for three teams is
shown on the graph below.
Which statement is true based on this information?
A. Team 3 always came
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B. Graphs
7, 1.1
Graphs are diagrams that show how two or more variables (or sets of
data) are related to one another. Graphs are drawn on a grid with
two axes:
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15. After three hours of travel, Car A is about how many kilometers
ahead of Car B?
A. 2
B. 10
C. 20
D. 25
Standard: Grade 7, 1.1
16. The graph below shows the t
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3. What is the probability that the arrow will not stop on red if you
spin it one time? (Assume that the spinner is fair.)
A
1
4
B
1
3
C
3
4
D
4
3
Standard: Grad
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Answer Key: Statistics & Probability
E. Independent Events
6, 3.5
Two events are independent if the outcome of the first event does
not affect the outcome of the second event.
Let's begin by compari
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6, 3.3
2. Brenda tosses a coin in the air. What is the probability that the
spinner will not land on heads? Express your answer as a fraction
and a percent.
1-
1
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Answer Key: Statistics & Probability
vii.
Line of Best Fit
7, 1.2
When there is a positive or negative relationship between data on a
scatter plot, we can best represent the relationship by drawing