Vocabulary
A _________________ is an entire group of object from which data can be collected.
population
P.360 #1a
What inference can you draw by comparing the medians?
Team B members generally trained for more days than team A members.
What is the mode of this data set?
16,17,28,28,28,33,33,35,35,36,37
28
What is the mode of this?
22,23,23,28,23,21,34,34,5,67,67,79
23
Making a conclusion by interpreting data is called making a(n) ________________.
Inference
P.360 #1b
What inference can you draw by comparing the interquartile range?
There is more variability in the number of days that team A members trained because the IQR for team A is greater than the IQR for team B.
What is the Mean of this data?
2,8,12,15,17,20,22,24
15
A(n) _____________________ is one that is true about a population based on a representative sample.
Valid Reference
P.360 #2
The dot plots show how long it took students in MR. Chauncey's two science classes to finish their science homework last night. Find the means to make an inference about the data.
The 1st period mean is 38.75. The 2nd period mean is 35. On average, it took students in the 1st-period class slightly longer to finish their homework than it did the students in the 2nd-period class.
How do we find the MAD?
Find the mean and subtract the mean from each number, then find the mean of that number
Oakley and Koby want to interview students to see how many students in the middle school like the food in the cafeteria. They survey 10 of their friends in their current classroom. Is this a valid inference/representative sample?
No, they did not give everyone an equal chance to be chosen.
A(n) _______________ accurately reflects the characteristics of an entire population.
P.358 #1
Anthony opened a new store and wants to conduct a survey to determine the best store hours. Which is the best representative sample?
A - A group of randomly selected people who come to the store in one week.
What is the range of this data?
17,19,29,39,39,41,42,44
17 to 44
Walker collects data from random 8th graders who want to get a Chick-fil-A in the school. Out of the 25 respondents, 15 wanted Chick-fil-A in the school. If the school has 150 students, how many students could we expect to want Chick-fil-A in the school?
90 students
How do we find the IQR?
Q3-Q1
P.358 #2
Becky wants to know if she should sell cranberry muffins at her bakery. She asks every customer who buys blueberry muffins if they would buy cranberry muffins. Is this a representative sample?
No, it does not include people who would buy cranberry muffins but do not like blueberry muffins.
Henry collects data from a random sample of seventh-graders. Out of 25 respondents, 10 ride the bus to school. Of the 150 seventh-graders who attend Harry's school, how many would be expected to ride the bus to school?
60 seventh-graders
Jimmy compares random download times of movies from three different services using the table below:
Who Knew: 4.9, 4.7, 5.4, 4.2, 4.8
Amazing Prince: 4.4, 4.4, 5.2, 4.8, 4.7
Peach Celsius: 4.6, 4.6, 4.9, 5.9, 5.0
Which service provides the fasted download speed?
Peach Celsius