Week one Math 221/ 50 Q&A/ Already Graded
A+
Mode - Answer: the most frequent number appearing in a data set
Mean - Answer: average
empirical rule - Answer: the percentage of data that falls within 1, 2 or 3 standard deviations of
the mean in a symmetrical bell-shaped distribution
standard deviation - Answer: the square root of the variance
Standard score - Answer: show how the particular data point is from the mean in the terms of
the number of standard deviations
Histogram - Answer: vertical bar chart that shows frequency on a y-axis
Page 1 of 6
, cluster sample - Answer: a sample where the population is divided into groups and several
groups are randomly selected from all from those selected
groups are sampled
Population - Answer: collection of all counts that are interested
sample - Answer: a subset, or part, of a population
stratified sample - Answer: a sample where the population is divided into groups and several
are randomly sampled form each group
qualitative data - Answer: consists of attributes, labels, or nonnumerical entries
frequency histogram - Answer: a graph shows vertical bars with the number points on the y-axis
and groups on the x-axis
In manufacturing, systematic sampling could be used to determine if the machines are
operating correctly. Which of the following best describes this type of sampling? - Answer:
Every 10th product in the line is selected
Which of the following data sets would you expect to have the smallest mean? - Answer: The
number of phones a person owns
In a normally distributed data set with a mean of 24 and a standard deviation of 4.2, what
percentage of the data would be between 19.8 and 28.2 and why? - Answer: 68% based on the
Empirical Rule
Page 2 of 6
A+
Mode - Answer: the most frequent number appearing in a data set
Mean - Answer: average
empirical rule - Answer: the percentage of data that falls within 1, 2 or 3 standard deviations of
the mean in a symmetrical bell-shaped distribution
standard deviation - Answer: the square root of the variance
Standard score - Answer: show how the particular data point is from the mean in the terms of
the number of standard deviations
Histogram - Answer: vertical bar chart that shows frequency on a y-axis
Page 1 of 6
, cluster sample - Answer: a sample where the population is divided into groups and several
groups are randomly selected from all from those selected
groups are sampled
Population - Answer: collection of all counts that are interested
sample - Answer: a subset, or part, of a population
stratified sample - Answer: a sample where the population is divided into groups and several
are randomly sampled form each group
qualitative data - Answer: consists of attributes, labels, or nonnumerical entries
frequency histogram - Answer: a graph shows vertical bars with the number points on the y-axis
and groups on the x-axis
In manufacturing, systematic sampling could be used to determine if the machines are
operating correctly. Which of the following best describes this type of sampling? - Answer:
Every 10th product in the line is selected
Which of the following data sets would you expect to have the smallest mean? - Answer: The
number of phones a person owns
In a normally distributed data set with a mean of 24 and a standard deviation of 4.2, what
percentage of the data would be between 19.8 and 28.2 and why? - Answer: 68% based on the
Empirical Rule
Page 2 of 6
