Stat 104 – Homework 8
Due Thursday March 22, 2012
Reading:
February 28 – March 6
March 20 – March 27
Chapter 6
Chapter 7
Assignment:
1. Complete the following problems from the text: 6.23, 6.24, 6.27, and 6.28.
Count
2. In the first lab data on the weights of unopened Fun Size bags of M&Ms were
collected. The data from last semester and this semester are combined and below is a
histogram of gross weight (contents and bag) for the Fun Size bags of M&Ms.
Gross Weight (g)
a) Describe the shape of the histogram. Why is it reasonable to use a normal model
for the distribution of the gross weight for all Fun Size bags of M&M’s?
b) Use a normal model with μ = 16.36 g, and σ = 1.29 g for the distribution of
weight of contents for Fun Size bags of M&M’s.
i. What is the probability that a Fun Size bag will have a gross weight less than
17 g?
ii. What is the probability that a Fun Size bag will have a gross weight greater
than 20 g?
iii. What is the probability that a Fun Size bag will have a gross weight between
16 g and 18 g?
iv. We wish to label the Fun Size bag such that 99.4% of all Fun Size bags will
have a gross weight at least the labeled weight. What should the labeled
weight be?
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