Statistics Homework 20 questions multiple choice
Question 1 of 20
5.0 Points
When sub-populations vary considerably, it is advantageous to utilize stratified sampling to ensure that each sub-population gets some representation and thus sampling error is reduced
A. True
B. False
Question 2 of 20
5.0 Points
Pretend you are in charge of a packaging equipment company that is filling boxes of cereal. From past experience we know the population’s mean weight of the filled boxes is 300 grams (and we know the distribution of grams is approximately normal). The population standard deviation is given as 24 grams. You are told to randomly select a sample of 144 boxes. You need to determine the probability that the sample of the 144 boxes will have a sample mean below 294. The probability will be between…
A. 0 and .010
B. .011 and .043
C. .044 and .150
D. .151 and .222
E. .223 and 1.0
Question 3 of 20
5.0 Points
With the inventions of email and other modern technology, non-response error has become and out-dated concern in statistics.
A. True
B. False
Question 4 of 20
5.0 Points
____________ reflects the variation or chance differences from sample to sample.
A. sampling error
B. non-response error
C. coverage error
D. measurement error
E. none of the above
Question 5 of 20
5.0 Points
An attractive 20 year old female named Cynthia arrives at Garret’s dorm room door. Garret answers the door and is immediately struck by Cynthia’s beauty. She asks him if she can have a few minutes of his time in order to complete a quick survey. He guesses that she is probably doing a survey about a political cause. Cynthia asks her first question, “how important is the environment to you”? In this scenario, we clearly need to be worried about…
A. the halo effect on measurement error
B. the potential problems caused from sampling error
C. non-response error
D. coverage error
E. none of the above, it’s college what do they need to be worried about.
Question 6 of 20
5.0 Points
The mean of all possible means (when dealing with a sampling distribution) will be equal to the population mean.
A. True
B. False
Question 7 of 20
5.0 Points
Determine the probability that a sample of 49 boxes will have a mean weight below 365 grams. Past records show that the population mean is 368 grams and the population standard deviation is 7. The probability will be between…
A. 0 and .110
B. .111 and .200
C. .201 and .399
D. .400 and .9730
E. .9731 and 1.0
Question 8 of 20
5.0 Points
Determine the probability that a sample of 196 boxes will have a mean weight below 400 grams. Past records show that the population mean is 398 grams and the population standard deviation is 21. The probability will be between…
A. 0 and .110
B. .111 and .200
C. .201 and .399
D. .400 and .9730
E. .9731 and 1.0
Question 9 of 20
5.0 Points
Determine the probability that a sample of 400 boxes will have a mean weight above 134.5 grams. Past records show that the population mean is 135 grams and the population standard deviation is 2. The probability that the sample will be above 134.5 will be between…
A. 0 and .110
B. .111 and .200
C. .201 and .399
D. .400 and .9730
E. .9731 and 1.0
Question 10 of 20
5.0 Points
Pretend you are in charge of a packaging equipment company that is filling boxes of cereal. From past experience we know the population’s mean weight of the filled boxes is 800 grams (and we know the distribution of grams is approximately normal). The population standard deviation is given as 24 grams. You are told to randomly select a sample of 144 boxes. You need to determine the probability that the sample of the 144 boxes will have a sample mean below 798. The probability will be between…
A. 0 and .010
B. .011 and .043
C. .044 and .150
D. .151 and .222
E. .223 and 1.0
Question 11 of 20
5.0 Points
For most populations, the sampling distribution of the mean is approximately normally distributed if samples of at least 30 are selected.
A. True
B. False
Question 12 of 20
5.0 Points
Determine the probability that a sample of 36 boxes will have a mean weight between 396 grams and 402 grams. Past records show that the population mean is 400 grams and the population standard deviation is 12. There will be ____________ probability that the sample is between 396 and 402…
A. approximately .8185
B. approximately .8641
C. approximately .0230
D. approximately .5461
E. approximately .4989
Question 13 of 20
5.0 Points
Let’s say we don’t know the population standard deviation and we are asked to create a 90% confidence interval. Our sample size is 14. Which value most accurately represents the critical value of “t” that you would use to plug in for your interval?
A. 1.7613
B. 1.7709
C. 1.96
D. 1.65
E. 1.8946
Question 14 of 20
5.0 Points
S is a symbol representing what statistic?
A. population mean
B. population standard deviation
C. sample size
D. the acceptable amount of error
E. the sample standard deviation
Question 15 of 20
5.0 Points
Here is your given information: the sample mean is 175, the sample size is 36, the sample standard deviation is 6, and you want an 80% confidence interval. The 80% confidence interval is best represented by…
A. 173.72 ≤ the population mean ≤ 176.28
B. 173.694 ≤ the population mean ≤ 176.306
C. 176.28 ≤ the population mean ≤ 173.72
D. 170.0 ≤ the population mean ≤ 180.0
E. 165.0 ≤ the population mean ≤ 185.0
Question 16 of 20
5.0 Points
Find the sample size: We desire to be within plus or minus 2 units. We will have a 90% confidence interval and the population standard deviation is 6. What is the estimated sample size?
A. the estimated sample size lies between 0 and 10
B. the estimated sample size lies between 11 and 20
C. the estimated sample size lies between 21 and 30
D. the estimated sample size lies between 31 and 40
E. the estimated sample size lies between 41 and 60
Question 17 of 20
5.0 Points
Find the sample size: We desire to be within plus or minus 5 units. We will have a 95% confidence interval and the population standard deviation is 10. What is the estimated sample size?
A. the estimated sample size lies between 0 and 10
B. the estimated sample size lies between 11 and 20
C. the estimated sample size lies between 21 and 30
D. the estimated sample size lies between 31 and 40
E. the estimated sample size lies between 41 and 60
Question 18 of 20
5.0 Points
Find the sample size: We desire to be within plus or minus 4 units. We will have a 95% confidence interval and the population standard deviation is 15. What is the estimated sample size?
A. the estimated sample size lies between 0 and 10
B. the estimated sample size lies between 11 and 20
C. the estimated sample size lies between 21 and 30
D. the estimated sample size lies between 31 and 40
E. the estimated sample size lies between 41 and 60
Question 19 of 20
5.0 Points
If you use the sample size equation and get a result of n=11.3095, how many people should you sample?
A. 11.3095
B. 12
C. 24
D. 23
E. 2.95
Question 20 of 20
5.0 Points
If you had a 83.84% confidence interval planned, the critical value you would use would be 1.40. Understand that you are given the following information: you know the population standard deviation is .55 and our sample size is 25.
A. True
B. False
