Question

1. A study is conducted on patients with arthritis to determine the effectiveness of an experimental treament for reducing joint pain in comparison with a control treatment. Two hundred patients are randomly assigned to the experimental and control treatments and patients report at the end of the study whether their joint pain has improved.
   
   

   Improvement

   Treatment	Yes	No
   Experimental	138	62
   Control	120	80

   
     
   Calculate the Odds Ratio. 2)

2. Lice are a pesky problem for school aged children and is unrelated to cleanliness. The lifetimes of lice that have fallen off the scalp onto bedding is approximately normally distributed with a mean of 2.2 days and a standard deviation of 0.4 days. What proportion of lice will die within 2.7 days?

3. The mean number of calories consumer per day for females aged 27 is 2725 with a standard deviation of 277. If a simple random sample of 100 females is selected, what is the probability that the mean number of calories ingested is more than 2800?

Answer 1

Let a be the no of patients in a treatment group whos joint pain is removed and b be the no of persons whos pain isnt removed.

Let c be yheno of persons in a control group whos pain is removed and d be the persons in same group whos pain isnt removed.

Odds ratio is.   

b)

Let X be the The lifetimes of lice that have fallen off the scalp onto bedding.

X ~ N (2.2 ,0.4)

P(X<2.7) =

= 0.8943

c)

Let X be the The mean number of calories consumer per day for females aged 27.

X~N(2725,277)

n=100