Vocabulary
6th Grade Review
Inferences on Data
Populations & Samples
Making Predictions
100
All of the people or residents in a town, country, or area.
What is Population
100
What is the MIDDLE value in a set of numbers called?
*Hint: You first have to rearrange the data values from least to greatest before finding your middle value*
Median
100
Which one has a faster commute time, morning or evening?
Morning
100
Two-thousand people live in a town. One-hundred of them were surveyed about their water usage in town.
What is the sample?
100 People
100
A bag contains 20 jelly beans. Seven of them are red. Thirteen of them are blue.
What percentage of the jellybeans are red?
7/20 or 35%
200
In a ______________________________, each member of the population has an equal chance of being included. This also tends to be a representative sample.
What is Random Sample
200
What is the INTER-QUARTILE RANGE in the Box & Whisker Plot?
33-27=6
200
Which of the three are used to find the variability or spread in a data set?
a. mean b. median
c. mode d. range
e. IQR f. MAD
Range, IQR, and MAD
200
What is the population?
The apricot trees at Jackson Grove
200
A sample of 20 jelly beans is pulled from a bag of 300. Seven of them are red. Thirteen of them are blue.
If seven of the twenty jellybeans sampled are red, about how many red jellybeans are in the bag?
7/20 times 300 = 105
300
A conclusion that is made by interpreting data.
What is Inference
300
What is the MEAN in the following set of numbers?
6.2 4.8 9.1 8.2 4.7 2.3 6.8 5.9
6
300
How much more is the total range between people at summer town meetings as opposed to people at winter town meetings?
Summer town meetings range: 50
Winter town meetings range: 35
50-35=15
300
Mr. Brown wants to see how well the 7th graders are going to do on their next assessment. Instead of testing everyone, he gives ten 7th graders at random a test sample to see how they do. How can Mr. Brown select these ten students at random to generate a representative sample? (Get Creative!)
-I can pick the first two students from each class that walk through the door
-Popsicle Sticks
-Every fifth student who walks through the door
300
A sample of 10 jelly beans is pulled from a bag of 500. One of them are red. Two of them are blue. Three of them are yellow. Four of them are green.
If three of the ten sampled jellybeans are yellow, about how many yellow jellybeans are in the bag?
3/10 times 500 = 150
400
An inference that is very likely to be true about a population based on a representative sample.
What is a Valid Inference
400
What is the MEAN ABSOLUTE DEVIATION in the following set of numbers?
6.2 4.8 9.1 8.2 4.7 2.3 6.8 5.9
12.6 divide 8 = 1.575
400
How much more is the mean commute time in the afternoon than the commute time in the morning?
Morning mean commute time: 24 minutes
Afternoon mean commute time: 27 minutes
3 minute difference
400
A population of 300 students are voting on who to vote for Student Council President. Fifteen percent of the student body were sampled to see how the vote would go.
How many students were sampled?
300 times 0.15 = 45
45 students
400
9/10 times 550 = 495
500
Give an example of a bias.
A bias is where the members of the sample are likely to vote in a particular manner because of their preference or affinity for one topic or another. Biased samples are most of the time NOT representative of a population.
500
Find the Inter-Quartile Range in the following data set
10 10 10 15 15 20 20 25 25 40
Q3: 25
Q1: 10
IQR: 15
500
What is the Mean Absolute Deviation for the long jump of the 7th graders?
Mean: 36.2
Deviations total: 56
MAD: 5.6
500
The state of AZ contains about 5 million registered voters. One-thousand of the voters were sampled to see how they would vote for a ballot. 55% voted in favor of the ballot and 45% voted against the ballot. If the sample is representative of the voting population of Arizona, how many more voters are expected to vote in favor of the ballot?
55% of 5,000,000 = 2,750,000 voters for ballot
45% of 5,000,000 = 2,250,000 voters against ballot
2,750,000 - 2,250,000 = 500,000
500
Lucy collects data from a random sample of seventh-graders. Out of 40 respondents, 7 attend after-school programs. Of the 200 seventh-graders attending Lucy's school, how many would be expected to attend after-school programs?
7/40 times 200 =35