Answer:
The value of E [Z] is 0.50.
Step-by-step explanation:
The expected value is computed using the formula:
Denote the three dices as follows:
X₁ = a four-sided die
X₂ = a six-sided die
X₃ = a 12-sided die
Define the indicator variables as follows:
The probability of rolling a 4 in the three dices are as follows:
Compute the value of E [Z] as follows:
Thus, the value of E [Z] is 0.50.
Answer:
For every 1000 pairs sold, the manufacturer expect to replace 239 pairs for free.
Step-by-step explanation:
Given:
Mean (μ) = 2.2, Standard deviation(S.D) (σ) = 1.7 years and x = 1 (1 year)
Let's find the Z score.
Z =
Now plug in the given values in the above formula, we get
Z =
Now we have to use the z-score table.
The z-score for 0.71 is 0.2611
Since it z is negative, so we subtract 0.2611 from 0.5000
0.5000 - 0.2611 = 0.2389
Percentage = 0.2389 × 100 = 23.89%
To find replaces for 1000 pairs, we need to multiply 23.89% by 1000
=
= 239
The cannot be in decimal, when we round off to the nearest whole, we get
239