Due date: Mar. 9, 2015.

- Use the data in

http://www.utdallas.edu/~ammann/stat3355scripts/BirthwtSmoke.csv- a.
- Construct a 95% confidence interval for the proportion of mothers who smoke.
- b.
- What sample size would be required to estimate this proportion to within 0.02 of the population proportion with 95% confidence if no prior bounds are used. What is this sample size if the sample proportion from part a is used as the prior bound?
- c.
- Construct a 95% confidence interval for the mean birth weight of newborns with mothers who smoke. Do the same for mothers who don't smoke.
- d.
- Use this data as a preliminary sample to determine the sample size required to estimate the mean birth weight for mothers who smoke to within 0.4 with 99% confidence. Do the same for mothers who don't smoke.
- e.
- Construct a 90% confidence interval for the s.d. of birth weight for mothers who smoke. Do the same for mothers who don't smoke.

- Use the data in

http://www.utdallas.edu/~ammann/stat3355scripts/crabs.txt- a.
- There are 4 combinations of species and sex (B-M, B-F, O-M, O-F) for the crabs in this data. Construct separate 95% confidence intervals for mean FL for each of these groups. Repeat for each of the other measurements, RW, CL, CW, BD.
- b.
- Construct a plot of RW versus BD using different colors for the two species and different plot symbols for Male and Female. Include a legend in the plot that shows which colors go with which species and which symbol goes with which sex.
- c.
- Obtain separate correlation coefficients between RW and BD for each of the 4 combinations of species and sex. Compare these correlations to the overall correlation between RW and BD using all crabs.

2015-02-25