Q 4 Ebola patients are to be treated with a new serum The pr

Q 4 Ebola patients are to be treated with a new serum. The probability of success with this serum in each patient is 0.4. What is the probability of only 2 successful treatments? Show appropriate formula and calculations.

Q Use the appropriate formula to determine the number of ways out of a hospital staff of 5 nurses, 2 nurses can be chosen to service the maternity ward.

Q   In a clinical trial, 10 subjects were to be divided equally between the experimental drug and the placebo. How many ways can they be assigned?

Q    In a community, number of adult Females = 3584 and number of adult males = 3831. Out of these, 43 females and 17 males are found to have heart disease. What is the proportion of females with heart disease?

Q    5 schizophrenic women ages 50- 59 and 10 eligible controls live in the same community. How many ways are there of selecting 5 controls?

Solution

Q1.Binomial Distribution

PMF of B.D is = f ( k ) = ( n k ) p^k * ( 1- p) ^ n-k
Where   
k = number of successes in trials
n = is the number of independent trials
p = probability of success on each trial

P( X = 2 ) = ( 4 2 ) * ( 0.4^2) * ( 1 - 0.4 )^2
= 0.3456

Q3.
the number of ways out of a hospital staff of 5 nurses, 2 nurses can be chosen
are = 5 C 2 ways = 5*4/2*1 = 10

Q4.

No. Of Female have heart disease (x)=43
Number of objects in a sample provided(n)=3584
Proportion Rate ( P )= x/n = 0.012