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.
No, because the sample is not chosen randomly.
Yes, because the manager asked everyone who entered the meat aisle.
Yes, because the manager asked everyone who entered the meat aisle.
No, because not all people who enter the meat aisle use coupons.
No, because not all people who enter the meat aisle use coupons.
Yes, because the sample contains coupon users and non-user
s.
Yes, because the sample contains coupon users and non-users.
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
retesting 100 light bulbs that have already been tested
retesting 100 light bulbs that have already been tested
testing the last 4,000 bulbs in the production line
testing the last 4,000 bulbs in the production line
testing every fiftieth light bulb in the production line
testing every fiftieth light bulb in the production line
testing the first 2,000 light bulbs in the production line
No because the people in the meat aisle are not a random sample. They do not buy light bulbs or bread for example. Many of us buy meat elsewhere.
testing every fiftieth light bulb in the production line
2/50 = 12/30 so 12 blunt pencils
I disagree with 100% of the answers, new record.
Thank you for pointing that out. It's important to note that the sampling method used by the store manager (surveying everyone who enters the meat aisle) is not a random sample and may not be representative of the entire population of shoppers in the store. A better approach would be to randomly select shoppers from different parts of the store or at different times to ensure a more diverse sample.
Regarding the colored pencils question, you are correct that the expected number of unsharpened pencils in the basket would be 2/50 * 300 = 12.
Thank you for your input and for helping us improve!
A middle school has 450 students. In a random sample of 100 students, 8 students indicated that they have traveled outside the United States. Predict the number of students at the middle school who have traveled outside the United States. (1 point)
students
In a random sample of 400 watches, 3 are defective. Out of a total of 10,500 watches, how many would you expect to be defective based on this sample data?
testing the last 4,000 bulbs 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
2
12
12
120
120
20
20
20
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?
Responses
251
251
141
141
125
125
52
Based on Tan’s sample data, approximately 125 students in the school prefer animated movies.
To find this, we can use proportional reasoning:
Animated movies were chosen by 48 out of 120 surveyed students.
So, the proportion of students who prefer animated movies is:
48/120 = 0.4
To estimate how many students in the whole school prefer animated movies, we can multiply this proportion by the total number of students:
0.4 * 628 = 251.2
Rounding to the nearest whole number, we get approximately 251 students.
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
110
110
45
45
195
195
41
41
Based on Pablo’s sample data, approximately 31 students in the school prefer orange sherbet.
To find this, we can look at the frequency of orange sherbet in the sample.
Orange sherbet was chosen by 10 out of 130 students surveyed.
To estimate how many students in the whole school prefer this flavor, we can use proportional reasoning:
10/130 = x/528
Solving for x, we get:
x = (10/130) * 528 = 40.6
Rounding to the nearest whole number, we get approximately 41 students.
We can use proportional reasoning to predict the number of students at the middle school who have traveled outside the United States:
- 8 out of 100 students in the sample have traveled outside the United States.
- We want to know the predicted number of students out of 450 who have traveled outside the United States.
- We can set up a proportion:
8/100 = x/450
- Solving for x:
x = (8/100) * 450
x = 36
Therefore, we can predict that approximately 36 students at the middle school have traveled outside the United States.