Statistics - review test 1
A market researcher asked a group of me and women to choose their favorite color design. The results are shown in the following table. Which of the following statement is not supported by the table?
For men, the number who chose a design with black was greater than the number who chose a design with blue.
One statistic calculated for pictures is called a run average. The following box plots summarize the ERA for pictures in two leagues. Based on the box plot, which of the following statistics is the same for both leagues?
The IQR
Which of the following questions about cars in a school parking lot will allow for the collection of a set of categorical data?
What are the colors of the cars in the lot?
The following list shows the selling prices of 8 houses in a certain town. What is the median selling price of the houses in the list?
$283,300
The following table graph shows the data for the 8 longest roller coasters in 2015; length (feet), type, speed (mph), height (feet), drop (feet), continent. Which of the following variables is categorical?
Type
Rodger claims that the two statistics most likely to change greatly when an outlier is added to a small set of data are the mean and the median. Is Rodger's claim correct?
No, the mean is likely to change greatly.
For which of the following distributions is the mean greater than the median?
*graph sloping to the right aka skewed right*
Janelle collected data on the amount of time in minutes each person in a large customers spent in a local store. The data was used to generate the box plot below. Which of the following statements is true?
Approximately half of the males in the sample of customers spent at least as much time in the store as any female in the sample of customers.
A graduate student conducted a study of field mice in rural Kansas. The student obtained a sample of 100 field mice and recorded the weight, in grams,of each mouse. After the measurements were taken, it was discovered that the scale was not calibrated correctly. The student adjusted the 100 recorded measurements by subtracting 3 grams from each. Which of the following statistics for the weight of the mice has the same value before and after the adjustment?
interquartile range (IQR)
Data was collected on the amount in dollars that individual customer spent on dinner in a restaurant. The qualities for this data is given below. Which of the following statements must be true for these customers?
At least half the customers spent less than or equal to $44.27 and half spent greater than or equal to $44.27.
Heights in inches for the 200 graduating seniors are summarized in the frequency table below. Which of the following statements about the median height is true?
It is greater than or equal to 60 inches but less than 66 inches.
The following pie chart summarizes the results of a survey given to airlines about the primary reason for flight delays. Which of the following statements is supported by the pie chart?
More delays were caused by weather than by all other reasons combined.
The following table summarizes the number of pies sold at a booth one day at a local farmers market. Which of the following tables is supported by the table?
The combined percentage of key lime pies sold and pumpkin pies sold was less than 50%.
A scientist recorded the duration of the eruptions of the Old Faithful geyser that occured in a one month period. The histogram below shows the distribution of the duration, in seconds, of the eruptions. Which of the following is the best description of the distribution.
The distribution displays two clusters, with one centered around 125 seconds and the other centered around 250 seconds,and has a range of at most 250 seconds.
| || ||| the histogram above shows the number of minutes needed by 45 minutes to finish playing a computer game. which of the following statements i correct?
The distribution is skewed to the left.
A sociologist collected data from a sample of people on their highest level of education and the number of times they visited any fast food restaurant during the previous week. The data is summarized by the bow plots below. Based on the box plots, which of the following statements must be true?
The interquartile range (IQR) from the number of visits at the more than 4 year university is less than the IQR for the number of visits at the community college level.
A random sample of 374 pennies was collected, and the age of each penny was determined. According to the boxplot below, what is the approximate IQR of the ages?
16
A sample of 100 students from Liberty high school and a sample of 60 students from Central high school were asked what they planned to do after graduation. Responses fell into five categories: four year university (4Y), community college (CC), join the military (M), or undecided (UD). The results are shown in the following bar chart. Which of the following statements is supported by the bar chart?
For the category undecided, the number of students from liberty high school was 4 greater than the number of students from central high school.
The following histogram summarizes the amount spent on plane tickets to travel home, in dollars, for a group of 30 students. If the interval size decreased from $200 to $100, which of the following must remain the same on the new histogram?
The sum of the frequencies.
Caffeine is known for reducing fatigue. A student wanted to investigate the caffeine content in sodas, energy drinks, tea, and coffee. The following data collected shows the amounts of caffeine for 12 popular drinks. 72, 55,34,45,28,70,7.5,165,80,105,40,35 a.) Construct an appropriate graphical display of the amounts of caffeine found in the 12 drinks. b.) Use the graph in part a to write a few sentences describing the distribution. c.) If a 12 ounce cup with 300 milligrams was added to the data set, how would the median and the mean of the new data set compare with the original?
a.) min=75, Q1=36.5, M=50, Q3=76, max=165, IQR=128.5 *box plot graph* b.) The center is about 50 and the IQR is about 128.5. This data is roughly symmetrical with no outliers. The mean is about 62.2083. C.) The median would be 55 and the mean would be 80.5. 300 is simply added to the set of data and then you recalculate the median/mean.
In the standard golf tournament, golfers play 18 holes on each of 4 consecutive days. For each hole, golfers keep track of the number of times they hit the ball before the ball goes into the cup. A golfer's score for the tournament is the total number of strokes needed to complete tournament 1 and the golfers who competed in tournament 2. Based on the box plots, which of the following statements must be true?
In both tournaments, at least half the golfers completed with a score less than 28.
Which of the following statements is true about a distribution that appears to have a gap when displayed as a histogram?
The distribution has a region between two data values where no data was observed.
An airline recorded the number of on time arrivals for a sample of 100 flights each day. The boxplot below summarizes the recorded data for one year. Which of the following statements must be true?
The difference between the median and the lower quartile for the number of on time arrivals is less than 2.
A magazine used the median instead of the mean when it reported the SAT score of the average student. A graphical display of the scores indicated the data was strongly skewed to the right. Which of the following explains why in this situation, the median is a more accurate indicator of the SAT score of the average student than mean is?
The man is affected by the skewness, the median is not.
The following histogram shows the age in years of the people who attended a documentary at a movie theater. Based on the histogram, which of the following statements best describes the relationship between the mean and the median of the distribution of ages?
The mean is most likely less than the median because the distribution is skewed to the left.
A zoologist recorded the ages in months of 55 bears and whether the bears were male or female. The data is shown in the back to back stemplot shown below. Based on the stem plot, which of the following statements is true?
The median age and the range of ages are both greater for female bears than male bears.
The following relative frequency table shows the political party affiliation for a sample of 500 people in a certain town. Which of the following statements is supported by the table?
The number of people affiliated with the Independents is 100.
A child psychologist asked 100 five year olds and 50 ten year olds to name their favorite color. The results are shown in the following table. Which of the following statements is supported by the table?
The percentage of five year olds who selected red or blue as their favorite color is greater than the percentage of ten year olds who selected red or blue as their favorite color.
Administrators at a university computed the mean GPA for chemistry majors and physics majors. The results are displayed in the table below. When the juniors and seniors are grouped together, could physics majors have a higher mean GPA than chemistry majors?
Yes, it could happen. Whether it does happen depends on the variability of the GPAs within each of the four groups of students
The graph below displays the scores of 32 students of a recent exam. Scores on this exam range from 64 to 95 points. a.) describe the shape of the distribution b.) Which summary statistic, the mean or the median, should the teacher use to report the overall exam performance was high? c.) The midrange (maximum + minimum)/2. Is the midrange considered a measure of center or spread?
a.) the distribution is unimodal, and it is skewed to the left. b.) the teacher should use the median because the mean is lower since the graph is skewed to the left c.) 9+6=15/2=7.5 The midrange is considered a measure of center because it indicates the halfway point.
A company wanted to determine health care costs of employees. A sample of 25 employees were interviewed and their medical expenses of the previous year were determined. Later the company discovered the highest medical expense was accidentally recorded 10 times. However, after correcting the error, the corrected amount was still greater than or equal to any other medical expense. Which of the following sample statistics must have remained the same after the correction was made.
median
The following box plot shows the typical gas mileage, in miles per gallon, for 20 different car models. Based on the box plot, the top 25 percent of the cars have a typical gas mileage of at least how many miles per gallon?
35
An amusement park attraction has a sign that indicates that a person must be 48 inches tall to ride the attraction. The following box plot shows the heights of a sample of people who entered the amusement park one day. Based on the box plot, approximately what percent of the people who entered the amusement park met the height requirements for the attraction?
50%
A random sample of 25 households was surveyed. Data was collected on the age of the youngest child living in each household. The histogram below displays the data collected in the survey. In which of the following intervals is the median of these data located?
8 to 10 years old
A school is having a contest in which students guess the number of candies in a jar. The number of candies guessed by male and female students is shown in the back-to-back stemplot below. Which of the following is true about the distribution of guesses?
The distributions of guesses for male and female students are both skewed to the left.
Grain moisture is a characteristic of grain that affects the price paid for the grain. A random sample of 28 loads of corn was evaluated for moisture as a percent of the total weight. A different random sample of 28 loads of soybeans was also evaluated for moisture. The data is displayed in the dot plots below. Based on the dot plots, which of the following is greater for the percent moisture of corn than the percent moisture of soybeans?
the range
The following frequency table shows the responses from a group of college students who were asked to choose their favorite ice cream flavor. Which of the following statements is not supported by the table?
One half of the students chose vanilla or chocolate.