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?
A. Yes, because the sample contains coupon users and non-users.
B.Yes, because the manager asked everyone who entered the meat aisle.
C. No, because not all people who enter the meat aisle use coupons.
D. No, because the sample is not chosen randomly
D. No, because the sample is not chosen randomly.
C. testing every 15th light bulb in the production line.
This sampling method is a type of systematic sampling, which can be used when there is a regular pattern in the population being sampled. By testing every 15th light bulb, the sample is likely to be representative of the overall population of light bulbs produced, and the results can be used to make a valid inference about the percentage of defective light bulbs in the production line.
Shouldn't be 12 if you cross multiply
We can use the sample proportion of students who prefer animated movies to estimate the population proportion, and then multiply that by the total number of students in the school to estimate the number of students who prefer animated movies.
- Proportion of students who prefer animated movies in the sample: 48/120 = 0.4
- Estimated proportion of students who prefer animated movies in the population: 0.4
- Estimated number of students who prefer animated movies in the population: 0.4 * 628 = 251
Therefore, the answer is C. Approximately 251 students in the school prefer animated movies.
We can use the proportion of students who prefer orange sherbet in the sample to estimate the proportion in the population, and then multiply that by the total number of students in the school to estimate the number of students who prefer orange sherbet.
- Proportion of students who prefer orange sherbet in the sample: 10/130 = 0.077
- Estimated proportion of students who prefer orange sherbet in the population: 0.077
- Estimated number of students who prefer orange sherbet in the population: 0.077 * 528 = 41
Therefore, the answer is D. Approximately 41 students in the school prefer orange sherbet.
a quality control manager wants to determine the percentage of a defective light bulbs in the production line which of the following sampling methods would most likely lead to a valid inference?
A. Testing the last 4,000 bulbs in the production line
B. Retesting 100 light bulbs that have already been tested
C. testing every 15th light bulb in the production line.
D. Testing the first 2000 light bulbs in the production line
if you randomly select 50 colored pencils from a basket and find that you are not sharpened if the basket contains 300 colored pencils how many would you expect to be unsharpened?
A. 2
B.20
C.12
D.120
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?
A.52
B.125
C.251
D.141
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?
A.45
B.195
C.110
D.41
The numbers of miles Ron biked are 31, 35, 49, 32, 45, 29, 33, 28, and 40.
Determine the range of this data set.(1 point)