STT 231 Exam 1 Questions With Correct
Answers
You asked ten of your classmates about their weight. On the basis of this
information, you stated that the average weight of all students in your university
or college is 142.6 pounds. This is an example of: - CORRECT ANSWER✔✔-statistic
A company has developed a new battery, but the average lifetime is unknown. In
order to estimate this average, a sample of 100 batteries is tested and the average
lifetime of this sample is found to be 250 hours. Identify population, sample,
variable, parameter, and statistic. - CORRECT ANSWER✔✔--Population: all new
batteries
-Sample: 100 tested batteries
-Variable: battery lifetime
-Parameter: average of all tested batteries
-Statistic: average of 250 hours
A recent Wall Street Journal poll asked a group of American voters to rate
economic conditions in the United States. 22% of the respondents rated economic
conditions as "favorable." Identify the population, sample, sample statistic, and
population parameter in this survey. - CORRECT ANSWER✔✔--Population: eligible
voters
-Sample: chosen voters
-Statistic: 22% favorability of sample
-Parameter: Percentage of all voters who would consider the economy favorable
, Quantitative data - CORRECT ANSWER✔✔-Naturally numbers, averages, height,
weight, age, GPA, credit hours, etc.
Qualitative data - CORRECT ANSWER✔✔-Not naturally numbered data, major, etc.
A recent study examined the intended travel destinations for a sample of
residents from Grand Rapids, Michigan. The respondents indicated the likely
destination of their next vacation. What are the units and variables? - CORRECT
ANSWER✔✔--Units: people who responded
-Variables: intended travel destination
For a class the average score was 70, the median 63 and standard deviation 13.
The instructor decided to add 5 points to all the scores. How will the mean,
median, and standard deviation change? - CORRECT ANSWER✔✔--Mean and
median will increase by 5 and standard deviation will not change.
When will the mean equal the median? - CORRECT ANSWER✔✔-Symmetrical
distribution
When will the mean be less than the median? - CORRECT ANSWER✔✔-Skewed
left (negatively skewed)
When will the mean be greater than the median? - CORRECT ANSWER✔✔-
Skewed right (positively skewed)
Answers
You asked ten of your classmates about their weight. On the basis of this
information, you stated that the average weight of all students in your university
or college is 142.6 pounds. This is an example of: - CORRECT ANSWER✔✔-statistic
A company has developed a new battery, but the average lifetime is unknown. In
order to estimate this average, a sample of 100 batteries is tested and the average
lifetime of this sample is found to be 250 hours. Identify population, sample,
variable, parameter, and statistic. - CORRECT ANSWER✔✔--Population: all new
batteries
-Sample: 100 tested batteries
-Variable: battery lifetime
-Parameter: average of all tested batteries
-Statistic: average of 250 hours
A recent Wall Street Journal poll asked a group of American voters to rate
economic conditions in the United States. 22% of the respondents rated economic
conditions as "favorable." Identify the population, sample, sample statistic, and
population parameter in this survey. - CORRECT ANSWER✔✔--Population: eligible
voters
-Sample: chosen voters
-Statistic: 22% favorability of sample
-Parameter: Percentage of all voters who would consider the economy favorable
, Quantitative data - CORRECT ANSWER✔✔-Naturally numbers, averages, height,
weight, age, GPA, credit hours, etc.
Qualitative data - CORRECT ANSWER✔✔-Not naturally numbered data, major, etc.
A recent study examined the intended travel destinations for a sample of
residents from Grand Rapids, Michigan. The respondents indicated the likely
destination of their next vacation. What are the units and variables? - CORRECT
ANSWER✔✔--Units: people who responded
-Variables: intended travel destination
For a class the average score was 70, the median 63 and standard deviation 13.
The instructor decided to add 5 points to all the scores. How will the mean,
median, and standard deviation change? - CORRECT ANSWER✔✔--Mean and
median will increase by 5 and standard deviation will not change.
When will the mean equal the median? - CORRECT ANSWER✔✔-Symmetrical
distribution
When will the mean be less than the median? - CORRECT ANSWER✔✔-Skewed
left (negatively skewed)
When will the mean be greater than the median? - CORRECT ANSWER✔✔-
Skewed right (positively skewed)
