Mathematics
Question 8
1. (Percentile) The weight of a product is normally distributed with a mean of four ounces and a variance of .25 “squared ounces.” The company wants to classify the unit as a scrap in a maximum of 1% of the units if the weight is below a desired value. Determine the desired weight such that no more than 1% of the units are below it.
1 points Question 9 1. (Percentile) An aptitude test has a mean score of 80 and a standard deviation of 5. The population of scores is normally distributed. What raw score corresponds to the 70th percentile?
1 points Question 10 1. (Percentile) During the past six months, 73.2% of US households purchased sugar. Assume that these expenditures are approximately normally distributed with a mean of $8.22 and a standard deviation of $1.10. 99% of the households spent less than what amount?

Question 1
1. For any sampled population, the population of all sample means is approximately normally distributed.
True
False
1 points
Question 2
1. If a population is known to be normally distributed, then it follows that the sample standard deviation must equal σ.
True
False
1 points
Question 3
1. If the sampled population is exactly normal distribution, then the sampling distribution of is also expected to be normal regardless of the sample size.
True
False
1 points
Question 4
1. The mean of the sampling distribution of is always equal to the mean of the sampled population.
True
False
1 points
Question 5
1. The central limit theorem states that as the sample size increases the distribution of the sample ________ approach the normal distribution.
medians  
means  
standard deviations  
variances 
1 points
Question 6
1. As the sample size ______________ the variation of the sampling distribution of ___________.
Decreases, decreases  
Increases, remains the same  
Decreases remains the same  
Increases, decreases  
None of the above 
1 points
Question 7
1. If the sampled population has a mean 48 and standard deviation 16, then the mean and the standard deviation for the sampling distribution of for n = 16 are:
4 and 1  
12 and 4  
48 and 4  
48 and 1  
48 and 16 
1 points
Question 8
1. A manufacturing company measures the weight of boxes before shipping them to the customers. If the box weights have a population mean and standard deviation of 90 lbs. and 24 lbs. respectively, then based on a sample size of 36 boxes, the probability that the average weight of the boxes will exceed 94 lbs. is:
34.13%  
84.13%  
15.87%  
56.36%  
16.87% 
1 points
Question 9
1. A manufacturing company measures the weight of boxes before shipping them to the customers. If the box weights have a population mean and standard deviation of 90 lbs. and 24 lbs. respectively, then based on a sample size of 36 boxes, the probability that the average weight of the boxes will be less than 84 lbs. is:
16.87%  
93.32%  
43.32%  
6.678%  
84.13% 
1 points
Question 10
1. In a manufacturing process a machine produces bolts that have an average length of 3 inches with a variance of .03. If we randomly select three bolts from this process: What is the standard deviation of the sampling distribution of the sample mean?
.03  
.01  
.1732  
.0577  
.10 