STATS 101
SHOW ME THE DATA
DESCRIBE & COMPARE
SAMPLING & BIAS
EXPERIMENTS & CONCLUSIONS
100
Population or Sample?
A researcher wants to know the average amount of sleep for all students at a high school. She surveys 100 randomly selected students and calculates their average hours of sleep.
What is a sample?
100
A teacher wants to display the frequency for favorite type of music reported by students in an AP Statistics class.
This type of graph would be most appropriate.
What is a bar graph?
100
A distribution of students’ daily screen time is strongly skewed to the right.
This measure of center would be more appropriate for describing a typical student: Explain why.
What is median because it is resistant to outliers?
100
A school district has 12 high schools. To survey students about a new school policy, researchers randomly select 3 of the 12 high schools and survey every student at those 3 schools.
This is the sampling method used.
What is cluster random sampling?
100
A researcher wants to investigate whether students who participate in an after-school sports program have higher average GPAs. She compares the GPAs of students who choose to participate in the program with those who do not.
This type of research took place.
What is an observational study?
200
A researcher records the number of hours each student spends studying for an AP Statistics test.
This is the type of variable being recorded.
What is a quantitative variable?
200
A dotplot shows the number of hours that 30 students spent studying for an AP Statistics test. The distribution has most observations between 2 and 5 hours, with a few students studying much longer.
This is the shape of the distribution.
What is skewed left?
200
A teacher records the number of hours students slept the night before a test. The distribution is strongly skewed to the left.
This combination would be most appropriate for describing the center and variability of the distribution.
What is median and IQR?
200
A school posts a survey on its Instagram account asking: “Do you think the school should add more parking spaces?”
This type of sampling bias is most likely present.
What is voluntary response bias?
200
A researcher wants to determine whether listening to music while studying improves test scores. Students choose whether they want to study with music or without music.
After the study, students who listened to music had higher average test scores.
This is a possible confounding variable.
What is the amount of time spent studying?
or
What is prior academic ability?
or
What is motivation?
or
What is study environment?
300
Parameter or statistic?
A high school has 2,000 students. The school calculates that 68% of all students at the school have a smartphone.
What is a parameter?
300
The following data represent the number of minutes 20 students spent studying the night before a test:
15, 20, 25, 25, 30, 30, 35, 40, 40, 45, 45, 50, 55, 60, 65, 70, 75, 80, 90, 120
This is the median.
What is 45?
300
A class has the following quiz scores:
72, 75, 78, 80, 81, 83, 85, 87, 90
The teacher discovers that she accidentally entered a score of 180 instead of 80 for one student.
This is what happened to mean, median, range, and IQR.
What is increases, stays the same, increases, stays the same?
300
A principal wants to learn how students feel about the school’s new cell phone policy. She obtains a list of all students and randomly selects 200 students from the list to complete a survey.
However, only 85 of the 200 selected students actually complete the survey.
This is the sampling method and the potential sampling bias.
What is simple random sample and nonresponse bias?
or
What is SRS and nonresponse bias?
300
A researcher randomly assigns 60 students to either use a new study app or continue using their normal study methods. After four weeks, the researcher compares the students' test scores.
These are the primary purpose of randomly assigning the students.
What is to help create groups that are similar, reducing the effect of confounding variables, AND allowing a cause-and-effect conclusion.
400
Which of the following is a statistical question?
A. How many students are in Mr. Dinh's AP Statistics class?
B. What is the average amount of time students at this school spend on their phones each day?
C. How many students are absent today?
D. What time does school start?
What is B?
or
What is the average amount of time students at this school spend on their phones each day?
400
The number of customers on any given day was recorded for Taco Wagon and Taco 'Bout It.
This is the comparison of the distributions' center and spread of customers for the two taco restaurants.
What is Taco Wagon's distribution has a median at about 78 customers which is less than Taco 'Bout It at 145 and, an IQR of about 90 which is greater than an IQR of about 20 for the opposing restaurant.
400
The scores on a quiz have a mean of 70 and a standard deviation of 8 points.
The teacher decides to transform every score using the formula:
New Score=1.1(Original Score)+10
This is the new mean and standard deviation.
What is 87 for mean and 8.8 for standard deviation?
400
A school wants to estimate the percentage of students who regularly eat breakfast.
Instead of randomly selecting students, the school surveys students standing in line at the cafeteria during breakfast.
This is the potential sampling problem (bias) and how it could affect the results.
What is undercoverage and overestimation on the proportion of students who regularly eat breakfast.
400
A school randomly selects 200 students from the entire student body. The selected students are then randomly assigned to either use a new tutoring program or continue with the school's regular study program.
After one semester, students in the tutoring group have a significantly higher average test score.
These conclusions were justified.
What is cause-and effect due to random assignment AND generalization due to random sampling?
500
A researcher wants to determine whether students at a high school spend more time playing video games on weekends than on weekdays. She randomly selects 200 students and records the number of hours each student plays video games on a randomly selected weekday and a randomly selected weekend day.
This is the identification for the following:
- The population
- The sample
- The observational units
- The variable being measured
What is...
1. All students at the high school
2. The 200 randomly selected students
3. The individual students
4. Number of hours spent playing video games
500
A histogram shows the salary of employees at Company X.
This is the description the distribution in context.
What is the distribution of salary made by employees at Company X is approximately symmetric, with a center between 40-50 thousand and no outliers. The histogram varies from 0 to 100 thousand?
500
A school is comparing the number of minutes students spend exercising each week. The distribution is approximately symmetric with no obvious outliers.
The mean is 142 minutes and the standard deviation is 28 minutes.
This is why the mean and standard deviation are appropriate statistics for describing this distribution.
What is because the distribution is approximately symmetric with no obvious outliers?
BONUS 100 points: Interpret the standard deviation in context.
500
A school district wants to estimate the percentage of all 12,000 high school students in the district who support adding a later start time.
There are four high schools in the district, with different numbers of students at each school.
The district wants every high school represented in the sample.
This is the appropriate sampling method to select 400 students.
What is stratified random sampling?
BONUS 100 points: Describe the entire process.
500
A researcher wants to determine whether a new energy drink improves athletic performance.
She recruits 80 high school athletes from one school. The athletes are randomly assigned to receive either the new energy drink or a placebo before completing a standardized athletic performance test. Neither the athletes nor the researchers interacting with them know which treatment each athlete receives.
The researchers find a statistically significant difference between the two groups.
These are two features of this study that strengthen the researchers' ability to conclude that the energy drink caused a difference in athletic performance.
What is random assignment?
or
What is control/placebo group?
or
What is blinding?
or
What is direct control?
BONUS 100 points: Explain the purpose of your 2 answers.