Question

What is the standard deviation of the number of recoveries among 48 patients when the
probability of recovering is 0.75?
(a) 36.
(b) 81.
(c) 9.
(d) 3.​

Answer 1

Question :- What is the standard deviation of the number of recoveries among 48 patients when the probability of recovering is 0.75 ?

(a) 36.

(b) 81.

(c) 9.

(d) 3.

Solution :-

given that,

→ Probability of recovering = P = 0.75

→ Total patients = n = 48 .

This is a binomial distribution.

we know that, . The variance of a binomial distribution is :- n * P * ( 1 - P ).

So,

Putting values we get,

→ variance = n * P * ( 1 - P )

→ variance = 48 * (0.75) * (1 - 0.75)

→ variance = 48 * (75/100) * (25/100)

→ variance = 48 * (3/4) * (1/4)

→ variance = (48 * 3) / 16

→ variance = 3 * 3

→ variance = 3².

Now, we know that,

→ Standard deviation = √(variance)

Therefore,

→ Standard deviation = √(3²)

→ Standard deviation = 3 . (Ans.) (Option D).

Learn more :-

for helping poor girls of their class, student save pocket money as shown in the following table find the median

Money S...

https://brainly.in/question/23808504