Math 160/263 Minitab Assignment # 8 - Windows Version
Chapter 4 - Sampling Distributions
1. A snack-food company uses a machine to package bags of pretzels. The bags are supposed to contain
454 grams (g). In fact, the contents vary according to a normal distribution with mean µ= 454 g and
standard deviation 7.5 g.
(a) Use the Calc >Probability Distributions >Normal menu command to find the probability
that an individual bag contains less than 445 g.
(b) Use the Calc >Calculator menu command to find the mean and standard deviation for the
contents of the bags in a carton of eight. Use the Calc >Probability Distributions >Normal
menu command to find the probability that the mean contents of the bags in a carton of eight is
less than 445 g.
2. A survey by the National Fisheries Institute showed that 25% of adults comsume seafood two or three
times a week. If 100 adults are selected at random, then the count of respondents that consume seafood
two or three times a week has a binomial distribution with parameters n= 100 and p= 0.25.
(a) Use the Calc >Random Data >Normal menu command to simulate 100 observations of this
random variable in each of 40 columns of the worksheet.
(b) Use the Calc >Row Statistics menu command to compute the row means for the first 10
columns, the first 20 columns, and all 40 columns.
(c) Create graphical and numerical descriptions of the results in columns 1, 41, 42, and 43.
(d) Briefly describe how the shapes of the distributions compare with one another, how the means
compare with one another, and how the standard deviations compare with one another.
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