A store manager wants to know the percentage of shoppers who use coupons. He surveys everyone who enters the meat aisle. He finds that 60 percent of shoppers use coupons. Does the sampling method the store manager used support a valid inference?(1 point)
Responses
No, because the sample is not chosen randomly.
Yes, because the manager asked everyone who entered the meat aisle.
No, because not all people who enter the meat aisle use coupons.
Yes, because the sample contains coupon users and non-users.
No, because the sample is not chosen randomly.
A quality control manager wants to determine the percentage of defective light bulbs in the production line. Which of the following sampling methods would most likely lead to a valid inference?(1 point)
Responses
testing every fiftieth light bulb in the production line
retesting 100 light bulbs that have already been tested
testing the last 4,000 bulbs in the production line
testing the first 2,000 light bulbs in the production line
testing every fiftieth light bulb in the production line.
Avery randomly selects 50 colored pencils from a basket and finds that 2 are not sharpened. If the basket contains 300 colored pencils, how many would you expect to be unsharpened?(1 point)
Responses
2
120
12
20
12.
There are 628 students in Tan’s high school. Tan surveys 120 randomly chosen students about their favorite movie genre. The results are as follows.
Movie genre Number of students/Frequency
Science Fiction 24
Horror 11
Comedy 27
Action 10
Animated 48
Based on Tan’s sample data, approximately how many students in the school prefer animated movies?
(1 point)
Responses
251
251
141
141
125
125
52
52
125.
To find out, we can set up a proportion:
Animated / Total = Surveyed Animated / Surveyed Total
Let's call the number of students who prefer animated movies "A". We know that the number of surveyed students who prefer animated movies is 48. The total number of surveyed students is 120. We can set up the proportion as:
A / 628 = 48 / 120
To solve for A, we can cross-multiply and simplify:
120A = 48 * 628
A = (48 * 628) / 120
A = 251.2
Rounded to the nearest whole number, this gives us 251. Therefore, approximately 251 students in the school prefer animated movies.
There are 528 students in Pablo’s high school. Pablo surveys 130 randomly chosen students about their favorite ice cream flavor. The results are as follows.
Ice cream flavor Number of students/Frequency
Strawberry 29
Butter Pecan 31
Chocolate 43
Orange Sherbet 10
Vanilla 17
Based on Pablo’s sample data, approximately how many students in the school prefer orange sherbet?
(1 point)
Responses
195
195
110
110
45
45
41
Based on Pablo’s sample data, approximately 31 students in the school prefer orange sherbet.
To find out, we can set up a proportion:
Orange Sherbet / Total = Surveyed Orange Sherbet / Surveyed Total
Let's call the number of students who prefer orange sherbet "O". We know that the number of surveyed students who prefer orange sherbet is 10. The total number of surveyed students is 130. We can set up the proportion as:
O / 528 = 10 / 130
To solve for O, we can cross-multiply and simplify:
130O = 10 * 528
O = (10 * 528) / 130
O = 40.8
Rounded to the nearest whole number, this gives us 41. Therefore, approximately 41 students in the school prefer orange sherbet.
The correct response is: No, because the sample is not chosen randomly.
Explanation: In order for a sample to support a valid inference, it should be chosen randomly. In this case, the store manager surveyed only the shoppers in the meat aisle, which means the sample is not representative of all shoppers in the store. It is possible that shoppers in the meat aisle have different coupon usage habits compared to shoppers in other aisles. Therefore, the sampling method used by the store manager does not support a valid inference on the percentage of shoppers who use coupons.