Center and Spread
Samples and Populations
Samples and Predictions
Vocabulary
More Statistics Problems
100
The weights of all the students in grade 9 are arranged from least to greatest. Which statistical measure separates the top half of this set of data from the bottom half? 1)mean; 2) mode; 3) median; 4) average
What is choice 3 (the median)?
100
To select a new school mascot, 20 randomly selected students in each grade were asked to choose between the two finalists: tiger and eagle. The results are: Grade 5: {Tiger =14; Eagle =6}; Grade 6:{Tiger =13; Eagle = 7}; Grade 7:{Tiger = 8 ; Eagle = 12}; Grade 8:{Tiger = 5; Eagle = 15}. Which statement is best supported by the results? A) The preferred mascot is a tiger. B) The preferred mascot is an eagle. C) Fifth and sixth grade students at the school preferred an eagle mascot. D) Seventh and eighth grade students at the school preferred an eagle mascot.
What is Choice D?
100
You chose a random sample of 10 students of the 7th graders in your room. If 3 of them like to dance, how many students can you predict who will like to dance from your classroom of 30 students?
What is 9?
100
What is a sample?
What is "a set of individuals or values chosen from a population"?
100
What is the range for data set B={3, 1, 7, 5, 6, 10, 8, 9, 9?
What is 9?
200
Which statement is true about the data set 3, 4, 5, 6, 7, 7, 10? 1) mean = mode; 2) mean > mode; 3) mean = median; 4) mean < median
What is Choice 3?
200
Abubakar randomly selected 60% of the seventh-grade students in his school and asked them their favorite subject. Of the students surveyed, 24 chose Math as their favorite subject. Based on the data, what is the most reasonable prediction of the number of seventh-grade students in his school who would choose Math as their favorite subject?
What is 40 students?
200

You ask 90 randomly chosen students if they like the cafeteria food.  There are 1500 students in the school. Predict the number of students in the school who like the cafeteria food.

What is 300 students?

200
What is a Random sample?
What is a sample selected in a way that gives every different possible sample of the same size an equal chance of being selected? (or a similar definition)
200
Mr. Taylor raised all his students’ scores on a recent test by five points. How were the mean and the range of the scores affected? A) The mean increased by five and the range increased by five. B) The mean increased by five and the range remained the same. C) The mean remained the same and the range increased by five. D) The mean remained the same and the range remained the same.
What is Choice B?
300
Find the mean, median and mode in the following test scores: 15, 16, 17, 17, 17, 17, 14, 15, 15, 16, 20, 21, 22, 22
What are Mean: 17.4 Median: 17.5 Mode: 17?
300
A school wants to add a coed soccer program. To determine student interest in the program, a survey will be taken. In order to get a random sample, which group should the school survey? A) every third student entering the building; B) every member of the varsity football team; C) every member in Ms. Zimmer’s drama classes; D) every student having a second-period French class.
What is choice A?
300
Two random samples about the number of pets per household in two different towns were taken. Sample 1 {0, 2, 3, 1, 1, 1, 3, 5}. Sample 2{1, 2, 0, 0, 4, 7, 3, 1}. On the same number line, draw a box plot for each sample. Then, based on their IQR explain which population you would expect to have more variability.
What is population 2 because its IQR is 3, as opposed to 2 for population 1?
300
What is Inference?
What is using data from a sample to draw conclusions about a population? (or a similar definition)
300
Find the range and outliers from the following exam scores: 87, 56, 57, 65, 34, 66, 75, 67, 87, 99, 84, 73, 79, 80
What are Range = 65 and Outliers: 34 and 99?
400

Mr. Vargas is trying to compare the exam scores of his 7th grade classes. He chose some students from both 71M and 72M. The scores for 71M were: 65, 85, 75, 90, 82, and 95. The scores for 72M were: 75, 74, 71, 95, 99, 85 and 75. What conclusion can Mr. Vargas reach about his two classes? A) 72M had a higher median score than 71M. B) 71M had a higher mean than 72M. C) 71M had a greater range than 72M.

What is C?

400

Four hundred licensed drivers participated in the math club's survey on driving habits. These were the age groups and the number of the participants: 16-25 years old = 150; 26-35 years old = 129; 36-45 years old =33; 46-55 years old = 57 ; 56-65 years old = 31. A) It may be biased because no one younger than 16 was surveyed. B) It would be fair because many different age groups were surveyed. C) It would be fair because the survey was conducted by the math club students. D) It may be biased because the majority of drivers surveyed were in the younger age intervals.

What is Choice D?

400

Two samples have the same mean. However, Sample 1 has a higher median than Sample 2. How can you explain this difference?

What is because Sample 1 has larger values in the middle?

400
What are Measures of center? List 3 measures of center.
What are values at the center or middle of a data set? Examples: Mean, Median, and Mode.
400
What is the IQR for the following data set? A={3, 6, 5, 10, 15, 26,13, 15}
What is 9.5?
500

Find the mean of the following set of data: 23, 24, 22, 30, 25, 26, and 32. 

What is 26?

500
If 6 and x have the same mean (average) as 2, 4, and 24, what is the value of x?
What is 24?
500
A random sample of 10 data values is taken: {2, 3, 7, 15, 30}. Explain which one, the mean or the median, will provide a better conclusion about the population.
What is the median because most values are closer to 7 than 30?
500
What are Measures of variability? List 2 measures of variability.
What are values that describe the variability or spread of a data set? Examples: Range, IQR, and MAD.
500
Which shows a good representation of a set of scores: mean, median or mode?
What is Median, because it shows the middle without being changed by any outliers?
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