Populations versus Samples
Random Sampling
Variability
Interpreting Dot plots
Mean and MAD
100
Ms. Stephens wants to compare average math grades of the students she teaches with the average math grades of all middle schoolers at Roland Park. For all middle schoolers the average math grade was a 72%, but for Ms. Stephens students the average math grade was 77%.
What is the population?
What is all middle schoolers at Roland Park.
100
True or False: A random sample is a process in which some members of the group are more likely to be chosen than others
What is False
100
True or False: As sample size increases, sampling variability decreases?
What is true
100
Based on the dot plot below, if I took another random sample would it be likely that it would have a value of 1? 
What is no it is not likely
100
Ms. Stephens took a random sample of size 8 of time (in minutes) her students spent on iReady. The data is: 43, 16, 32, 26, 61, 35, 29, 19
What is the mean for Ms. Stephens’ sample?
What is 32.625
200
Ms. Stephens wants to compare average math grades of the students she teaches with the average math grades of all middle schoolers at Roland Park. For all middle schoolers the average math grade was a 72%, but for Ms. Stephens students the average math grade was 77%.
What is the sample in this scenario?
What is Ms. Stephens' studnets
200
Roland Park wants to get student and teacher opinions on the dress code policy at the school. Select all of the following statements that describe a random sample?
All student and teacher names are put on a wheel and it is spun to choose a person
The sample includes all students and teachers who have a first name that starts with an M
All the names of students and teachers are put on a list. The sample is selected by choosing every 15th person.
All the names are put into a computer and it randomly generates names
The names of students are put into a computer and it randomly generates names
What is 1, 3, and 5
200
What is the sampling variability of the dot plot below
What is 5-13
200
Would 8 be a good estimate for the hours of sleep a student gets on the weekend? Why or why not?
What is no because it only has 3 dots and because it is towards the edge of the plot
200
Calculate the men's life span mean AND the women's life span mean from the table below
What is 77.2 for men and 78.2 for women
300
Ms. Stephens wants to compare average math grades of the students she teaches with the average math grades of all middle schoolers at Roland Park. For all middle schoolers the average math grade was a 72%, but for Ms. Stephens students the average math grade was 77%.
What is the sample statistic in this scenario?
What is the average math grade is 77%
300
Which of the following do not describe random samples? Why?
All student and teacher names are put on a wheel and it is spun to choose a person
The sample includes all students and teachers who have a first name that starts with an M
All the names of students and teachers are put on a list. The sample is selected by choosing every 15th person.
All the names are put into a computer and it randomly generates names
The names of students are put into a computer and it randomly generates names
What is 2 and 4, because they exclude some members of the population (i.e. not everyone has a equal chance of being selected)
300
Which dot plot below has the largest variability?
What is Elena's dot plot
300
What is the shape of the dot plot below? Right-skewed, left-skewed, or symmetric
What is left-skewed
300
Students that get 7 or less hours of sleep have an average math grade of of 81.1, while students that get more than 7 hours of sleep have an average math grade of 87.5. What is the difference between the two means and which group performs better in math?
What is 6.4 and those who sleep more than 7 hours
400
Ms. Stephens wants to compare average math grades of the students she teaches with the average math grades of all middle schoolers at Roland Park. For all middle schoolers the average math grade was a 72%, but for Ms. Stephens students the average math grade was 77%.
What is the population characteristic in this scenario?
What is the average math grade is 72%
400
True or False: If I take two different samples from the same population they will be exactly the same
What is False
400
A meteorologist took a sample of 100 days from last year to estimate the proportion of rainy days. Would the sampling variability increase or decrease if the meteorologist instead took a sample of 75 days? Why?
What is increase because they sample size is smaller
400
What would be a good estimate for the mean hours of sleep for the dot plot below?
What is between 10 - 11 hours
400
Ms. Stephens took a random sample of size 8 of time (in minutes) her students spent on iReady. The data is: 43, 16, 32, 26, 61, 35, 29, 19.
If the mean of this data is about 33, what is the MAD?
What is 10.375
500
What is the difference between a population characteristic and a sample statistic?
A population characteristic is a number that describes the entire population, while the sample statistic is a value that describes a sample and is an estimate of the population
500
If you took another random sample from the population to add to the dot plot below is it more likely that the random sample would be between 6-8 hours of sleep or that it would be between 10-12 hours of sleep?
What is 10-12 hours of sleep
500
Which dot plot is likely to have had the smallest sample sizes? Why?
What is Elena's dot plot because it has the largest variability
500
Select all of the options that are true about the plots below
1. The two dot plots are likely to have the same mean
2. The is no overlap between the two dot plots
3. The distribution for the top dot plot is skewed right
4. The distribution for the bottom dot plot is symmetric
What is 3 and 4
500
Students that get 7 or less hours of sleep have an average math grade of of 81.1, while students that get more than 7 hours of sleep have an average math grade of 87.5. What is the difference between the two means and which group performs better in math? The MAD for the first group is 4.3 and the MAD for the second group is 4.6. Is there a meaningful difference between means? Why or why not?
What is no because when calculated the difference is 1.39 which is less than 2