|Posted: 21 September 2007 at 10:14am | IP Logged
Is there anyone out there who knows anything about biostatistics. I have a homework assignment due Monday and I have no clue how to solve one of the problems. Here's what the paper says,
An animal physiologist studied the pituitary function of hens put through a standard forced molt regimen by using egg producers to bring the hen back into egg production. 25 hens were used for the study. 5 hens were used for the measurements at the premolt stage prior to the forced molt regimen and at the end of each of 4 stages of the forced molt regimen. The 5 stages of the regimen were (1) premolt (control), (2) fasting for 8 days, (3) 60 grams of bran per day for 10 days, (4) 80 grams of bran per day for 10 days, and (5) laying mash for 42 days. The objective was to follow various physiological responses associated with the pituitary of the hen during the regimen to aid in explaining why the hens will come back into production after forced molt. one of the compounds measure was serum T3 concentration. The data in the table are the serum T3 measurements for each of the five hens scarified at the end of each stage of the regimen.
Treatment Serum T3, (ng/dl) x 10-1
Premolt 94.09; 90.45; 99.38; 73.56; 74.39
Fasting 98.81; 103.55; 115.23; 129.06; 117.61
60 g bran 197.18; 207.31; 177.50; 226.05; 222.74
80 g bran 102.93; 117.51; 119.92; 112.01; 101.10
Mash 83 .14; 89.59; 87.76; 96.43; 82.94
A) Write a linear statistical model for this study and explain the model components.
B) State the assumptions necessary for an analysis of variance of the data.
C) Compute the analysis of variance for the data and test the hypothesis of no difference among means of the five treatments at 0.05 level of significance.
D) Compute the 95% confidence interval estimates of the treatment means.
E) Determine how many chickens the biologist would need for each treatment to reject the null hypothesis at the 0.05 level of significance with a power of 0.90 if the difference between the control treatment and any new treatment was 30 units of T3 concentration.
I need someone to help point me in the right direction on getting started with this problem. Here's my issues,
- I have no idea what part A is asking
- Is part C asking for a single factor analysis of variance (one-way ANOVA) or am I supposed to use a different test (i.e. random effects analysis of variance, Bartlett's, etc)?
- What is part E talking about?
Please note, I am looking for help on this question. By no means do I want someone to solve it for me, just point me in the right direction for solving it. Also, although I appreciate the offer, I do not have the money to pay a tutor so please don't offer to tutor me unless you can do it for free.
EDIT: By the way, I do have the SAS program to help with creating ANOVA Tables.
Edited by Little_ash_2003 on 21 September 2007 at 10:20am