Biased/Unbiased Samples
To determine whether students have heard about New Product X, a research company surveys randomly selected students from a computer-generated list. Is this simple, stratified, or systematic?
simple random sample
A football coach is planning on purchasing training videos for each player who misses his summer camp. He randomly asks 15 players, and 4 of them say they will miss the camp. How many players out of 75 can the coach expect to miss the summer camp?
20 players
The third planet from the sun
What is the Earth?
The constant of proportionality: y=-1/5x
What is -1/5?
In order to analyze how much money the average customer spends on lunch at a diner, the owner takes 15 random samples of 20 lunch bills each. The graph shows the mean of each sample (rounded to the nearest $0.50).
Which value is an appropriate estimate of the population mean, rounded to the nearest $0.50?
$6
To determine whether there is enough interest in starting a high school water polo team, a coach surveys 15 randomly selected junior high students from the swim team and dive team.
stratified random sample
A high school principal is planning to start a new elective class. He randomly surveys 60 students to ask whether they would take the class, and 7 said they would. How many students can the principal expect to take the class if there are 540 students in the high school?
63 students
The numbers of days in a year.
What is 365 days?
The prime factorization of 512.
What is 29.
The double box plot shows the daily number of different size buckets of range balls sold at a driving range. What is the median of Medium and Jumbo Bucket?
Medium - 21
Jumbo - 25
To select a new school mascot, all students are invited to take a survey. The responses will determine the new mascot. Is this convenience sample or voluntary response sample?
voluntary response sampling
A teacher is planning on buying materials for a project all her classes will complete. She randomly surveys 24 students about what method they will use to present their project. The table shows the results. How many poster boards can the teacher expect to buy if she has 96 students in total?
Material for Project: # students
poster board 11
electronic 7
construction paper 6
44 poster boards
The first vice president of the United States of America.
Who is John Adams?
What is x>-5?
The double box plot shows the daily number of different size buckets of range balls sold at a driving range. What is the Interquartile range of Medium and Jumbo Bucket?
Medium - 8
Jumbo - 4
A travel agent surveys local clients to determine how many people in the state are planning on taking a vacation in the upcoming year. The responses will determine the agency’s marketing strategy. Is this voluntary response or convenience sample?
convenience sample
An employer is planning to buy lunch for all his employees. The table shows the results of a random survey of his employees’ lunch preferences. How many Italian sandwiches can the employer expect to buy if he has 84 employees?
Sandwich Preference Percent
Italian 25%
Veggie 20%
Turkey 55%
21 Italian sandwiches
What is Au?
What is 33% of 84. Round to the nearest hundredth place.
What is 27.72?
The wholesale cost of a surfboard at a store is $660. The markup for the surfboard is 45%.
What is the selling price of the surfboard?
$957
Identify the sample method used and whether it is biased or unbiased. Then determine whether the inference is valid. To evaluate whether customers enjoy the barista’s new smoothie, a restaurant manager surveys every other customer who orders the new smoothie. The manager determines that customers enjoy the new smoothie.
systematic random sample; unbiased; The inference is valid.
The table for payment methods at a grocery store are shown in the graph. Predict how many customers will pay with their phones if 800 customers visit the store.
Payment Method: Percent:
Cash 26%
Check 8%
Credit 52%
Phone 14%
112 people
The city nicknamed the Windy City.
What is Chicago?
3(2x - 9) + 7 = 4
What is x=4
If a black marlin fish swims 13 miles in 25 minutes, how any miles does it swim per hour?