STAT 101 Lecture Notes - Lecture 13: Standard Deviation, Underweight
SchoolIowa State University
Course CodeSTAT 101
This preview shows page 1. to view the full 4 pages of the document.
Statistics 104 - Laboratory 8
Often a population will have a variable whose distribution can be modeled using a normal
model with a population mean μ and a population standard deviation σ.
1. Market weight of gilts.
The market weight, in pounds, of 179 gilts, female hogs is displayed in the histogram
150 200 250 300 3
a) Describe the shape of the distribution. Why is a normal model a reasonable
model for the distribution of the population of gilt market weights?
b) Use a normal model for the population of gilt market weights with population
mean μ = 236.5 pounds and population standard deviation σ = 31.2 pounds to find
• The probability that a gilt market weight will be less than 300 pounds.
• The probability that a gilt market weight will be greater than 275 pounds.
• The probability that a gilt market weight will be between 200 and 300
• The value such that 4% of all gilt market weights will be less than that
• The value such that 25% of all gilt market weights will be greater than that
• The values such that the middle 90% of all gilt market weights will fall
between those values.
Market Weight (lbs)
You're Reading a Preview
Unlock to view full version