MATH 221B STATISTICS UNIT 3 |
PRACTICE QUESTIONS AND DETAILED
ANSWERS | GRADED A+ |
GUARANTEED SUCCESS
Updated 2026 Questions and Answers | 100% Verified
Exam Prep
,In a pie chart, why are the slices (sectors) different sizes? Each slice represents a category and the area of each slice represents the proportion of
the total occupied by the category.
The size of each slice is random.
The size of each slice is determined by the number of
categories.
Each slice represents a category and the area of each slice
represents the proportion of the total occupied by the
category.
Pie charts are more visually appealing when the slices are
different sizes.
How are Bar charts and Pareto charts related? The only difference between a Bar chart and a Pareto chart is that the bars in a Pareto
chart are ordered largest to smallest going from left to right.
Pareto charts are constructed from tossing a coin several
times.
They are identical.
The only difference between a Bar chart and a Pareto chart is
that the bars in a Pareto chart are ordered largest to smallest
going from left to right.
Use the following information for the next 3 questions. True proportion
We conclude that p^ is normally distributed if np≥10 and
n(1−p)≥10.
Is p the true proportion or the sample proportion?
Sample proportion
True proportion
What is n? The sample size.
The number of successes.
The number of candidates in an election.
The sample size.
, If p=1/4, what is the smallest n that satisfies the requirement? 40
Use the following information to answer the next 2 questions. 0.4
Suppose n=24 and p=0.4.
What is the mean of p^? (Round answer to the tenth place.)
What is the standard deviation of p^? (Round answer to the 0.1
tenth place.)
Use the following information to answer the next 4 questions. 0.35
Brittnie's batting average is 0.300. We want to determine the
probability she will get more than 35 hits in her next 100 at
bats (n=100 and p=0.3).
What is p̂? (Round to two decimal places.)
What is the standard deviation of p^? (Round to three decimal 0.046
places.)
What is the z-score? (Round to three decimal places.) 1.091
What is the probability Brittnie gets at least 35 hits in her next 0.138
100 at bats? (Round to 3 decimal places.)
Use the following information for the next 3 questions. 0.011
If the true proportion of people who support a political
candidate is p=0.52 and if n=2000 people are surveyed, we
want to determine the probability that the results of the survey
will suggest the candidate is losing the election (getting less
than 50% of the votes).
What is the standard deviation of p^? (Round to 3 decimal
places.)
What z-score would you use? (Round to 3 decimal places.) -1.79
PRACTICE QUESTIONS AND DETAILED
ANSWERS | GRADED A+ |
GUARANTEED SUCCESS
Updated 2026 Questions and Answers | 100% Verified
Exam Prep
,In a pie chart, why are the slices (sectors) different sizes? Each slice represents a category and the area of each slice represents the proportion of
the total occupied by the category.
The size of each slice is random.
The size of each slice is determined by the number of
categories.
Each slice represents a category and the area of each slice
represents the proportion of the total occupied by the
category.
Pie charts are more visually appealing when the slices are
different sizes.
How are Bar charts and Pareto charts related? The only difference between a Bar chart and a Pareto chart is that the bars in a Pareto
chart are ordered largest to smallest going from left to right.
Pareto charts are constructed from tossing a coin several
times.
They are identical.
The only difference between a Bar chart and a Pareto chart is
that the bars in a Pareto chart are ordered largest to smallest
going from left to right.
Use the following information for the next 3 questions. True proportion
We conclude that p^ is normally distributed if np≥10 and
n(1−p)≥10.
Is p the true proportion or the sample proportion?
Sample proportion
True proportion
What is n? The sample size.
The number of successes.
The number of candidates in an election.
The sample size.
, If p=1/4, what is the smallest n that satisfies the requirement? 40
Use the following information to answer the next 2 questions. 0.4
Suppose n=24 and p=0.4.
What is the mean of p^? (Round answer to the tenth place.)
What is the standard deviation of p^? (Round answer to the 0.1
tenth place.)
Use the following information to answer the next 4 questions. 0.35
Brittnie's batting average is 0.300. We want to determine the
probability she will get more than 35 hits in her next 100 at
bats (n=100 and p=0.3).
What is p̂? (Round to two decimal places.)
What is the standard deviation of p^? (Round to three decimal 0.046
places.)
What is the z-score? (Round to three decimal places.) 1.091
What is the probability Brittnie gets at least 35 hits in her next 0.138
100 at bats? (Round to 3 decimal places.)
Use the following information for the next 3 questions. 0.011
If the true proportion of people who support a political
candidate is p=0.52 and if n=2000 people are surveyed, we
want to determine the probability that the results of the survey
will suggest the candidate is losing the election (getting less
than 50% of the votes).
What is the standard deviation of p^? (Round to 3 decimal
places.)
What z-score would you use? (Round to 3 decimal places.) -1.79
