Statistics TN Ready Review

A clothing store manager wants to make sure the paint color on the walls appeals to customers. Which sampling method produces an unbiased, representative sample of the population?

• Survey 35 randomly selected customers at the clothing store each day for 7 days.

• Survey 150 people at the food court in the mall.

• Survey every 5th person who enters the food court at the mall.

• Survey every customer at the clothing store on Sunday who is under the age of 30.

Which statement is true?

• A probability of 1 indicates an event is unlikely to happen

• A probability of 4/5 indicates an event is likely to happen.

• A probability of .25 indicates an event will definitely not happen.

• A probability of -1 indicates an event will definitely happen.

The data shows the lengths, in inches, of 6 snakes.

5, 7, 8, 9, 12, 15

What is the median of the data set?

• 5

• 8.5

• 9

• 9.3

• Team 1 typically spends more hours each week working out together than Team 2 because the interquartile range of Team 1 is larger.

• Team 1 typically spends more hours each week working out together than Team 2 because the median of Team 1 is larger.

• Team 2 typically spends more hours each week working out together than Team 1 because the interquartile range of Team 2 is larger.

• Team 2 typically spends more hours each week working out together than Team 1 because the median of Team 2 is larger.

• On average, about 50% of lifeguards prefer either No More Rays or Protect-O.

• On average, about 40% of lifeguards prefer Sun Shield.

• On average, about 3/4 of lifeguards prefer either No More Rays or Sunny Days.

• On average, about 1/4 of lifeguards prefer Sun Shield.

If a data set is symmetrical, which statistical measure best represents the entire spread of the data set?

• interquartile range

• mean

• median

• range

• The difference in the medians is about 1.3 times the interquartile range of tickets sold per game for either sport.

• The difference in the medians is about 1/2 times the interquartile range of tickets sold per game for either sport.

• The difference in the medians is about 2 times the interquartile range of tickets sold per game for either sport.

• The difference in the medians is equal to the interquartile range of tickets sold per game for either sport.

A student collects data to determine the favorite sport among seventh graders at the middle school. Which sampling method produces an unbiased, representative sample of the population?

• Ask 10 randomly selected students from each seventh-grade homeroom.

• Ask every seventh-grade student who rides the bus to school in the morning.

• Ask every student in the middle school who plays a fall sport.

• Ask the first 30 students to arrive to the middle school each morning.

A statistician looks at a set of data that is skewed left and contains an outlier. Which statement is true?

• The statistician should use the mean and interquartile range as the best measures of center and variability to represent the data.

• The statistician should use the mean and the range as the best measures of center and variability to represent the data.

• The statistician should use the mean and range as the best measure of center and variability to represent the data.

• The statistician should use the median and range as the best measures of center and variability to represent the data.

• The mean number of miles students on Team 1 run is equal to the mean number of miles student son Team 2 run.

• The median number of miles students on Team 1 run is equal to the median number of miles students on Team 2 run.

• The range in the number of miles students on Team 1 run is greater than the range in the number of miles studnets on Team 2 run.

• The range in the number of miles students on Team 2 run is greater than the range in the number of miles students on Team 1 run.