Question

1. Suppose the value of a stock varies each day from $16 to $25 with a uniform distribution. Find s.

Group of answer choices

A. 20.5

B. 11.8

C. 17

D. 2.6

2. Find the mean of the probability distribution:

   x P(x)   
2 0.33

3 0.24
4 0.43

Group of answer choices

A. 2.60

B. 3.10

C. 1.60

D. 2.10

3. The number of cartoons watched by Mrs. Kelly's first grade class on Saturday morning is shown below:

   x P(x)   
0 0.15

1 0.20
2 0.30
3 0.10
4 0.20

5 0.05

Calculate the standard deviation for this probability distribution.

Group of answer choices

A. 1.18

B. 1.89

C. 1.46

D. 2.25

4. Let's suppose the days in the hospital of admitted Covid-19 patients are uniformly distributed between 3 to 18 days. Find the days in the hospital of the middle 50%. Round answer(s) to two decimal places.

Answer 1

Given:

1) Suppose the value of a stock varies each day from $16 to $25 with a uniform distribution.

Here a = 16, b = 25

For uniform distribution :

s = (b-a)/√12 = (25-16)/√12 = 2.6

So s = 2.6

Answer - option D

2)Given :

x P(x)   
2 0.33

3 0.24
4 0.43

The mean of the probability distribution:

E(X) = xP(x) = 2*0.33 + 3*0.24 + 4*0.43

= 0.66 + 0.72 + 1.72

= 3.10

E(X) = 3.10

Answer - option B

3)

The number of cartoons watched by Mrs. Kelly's first grade class on Saturday morning is shown below:

   x P(x)   
0 0.15

1 0.20
2 0.30
3 0.10
4 0.20

5 0.05

Mean distribution of the data is

= 2.15

E(X2) = 0²(0.15) + 1²(0.20) + 2²(0.30) + 3²(0.10) + 4²(0.20) + 5²(0.05)

= 6.75

Hence,

Standard deviation = = 1.46

Answer - option C