Ivo Dinov
UCLA Statistics, Neurology, LONI
, Math/PIC
 Courses SOCR Ivo Dinov's Home SiteMap Software Contact

STAT 13 (1a, 1b, 1c)

Introduction to Statistical Methods for the Life and Health Science

Department of Statistics

## Instructor: Ivo Dinov

Homework 3
Due Date: Monday, Oct. 22, 2007

Please, submit your homework right before lecture on the due date. See the HW submission rules. On the front page include the following header.
• (HW_3) Do the following problems on pages 131-147, Samuels & Witmer's text Statistics for the Life Sciences, Prentice Hall (2003).
• 4.3: The brain weights of adult Swedish males are approximately normally distributed with mean μ = 1,400g and standard deviation 100g. Let Y denote the brain weight of a randomly chosen person from this population. Calculate:
• P(Y <=1,500).
• P(1,325 <= Y <=1,500).
• P(1,325 <= Y).
• P(1,475 <= Y).
• P(1,475 <= Y <=1,600).
• P(1,200 <=Y <=1,325).
• 4.9: The serum cholesterol levels of 17-year-olds follows a normal distribution with mean 176 mg/dLi and standard deviation 30 mg/dLi. What percentage of 17-year-olds have serum cholesterol values:
• 186 or more?
• 156 or less?
• 216 or less?
• 121 or more?
• between 186 and 216?
• between 121 and 156?
• between 156 and 186?
• 4.19:  The June precipitation totals, in inches" for the city of Cleveland, OH are given below. Use these values to create a normal probability plot of the data. Do you conclude that these data are Normally distributed?

 Year Rainfall Normal_Score 1964 2.06 -0.94 1965 3.05 -0.52 1966 1.83 -1.23 1967 1.17 -1.71 1968 2.32 -0.71 1969 4.61 0.52 1970 4.98 0.94 1971 3.79 0.16 1972 9.06 1.71 1973 6.72 1.23 1974 3.57 -0.16 1975 4.10 0.33 1976 3.64 0.00 1977 4.91 0.71 1978 3.30 -0.33
• 4.24: The litter size of a certain population of female mice follows approximately a normal distribution with mean 7.8 and standard deviation 2.3. Let Y be the size of a randomly chosen litter. Use continuity correction to find approximate values for these probabilities:
• P(Y <= 6)
• P(Y = 6)
• P8 <= Y <= 11)
• 4.29: The heights of a certain population of corn plants follows a normal distribution with mean 145 cm and standard deviation 22 cm.What percentage of the plant heights are:
• 100 cm or more?
• 120 cm or less?
• Between 120 and 150 cm tall?
• Between 100 and 120 cm tall?
• 180 cm or more?
• 150 cm or less?
• 4.41:  Resting heart rate was measured for a group of subjects; the subjects then drank 6 ounces of coffee. Ten minutes later their heart rates were measured again. The change in heart rate followed a normal distribution, with mean increase of 7.3 beats per minute and a standard deviation of 11.1. Let Y denote the change in heart rate for a randomly selected person. Find:
• P(Y > 10).
• P(Y > 20).
• P(5 < Y < 15).

 Ivo Dinov's Home http://www.stat.ucla.edu/~dinov Visitor number, since Jan. 01, 2002 © I.D.Dinov 1997-2008