A car is designed to last an average of 12 years with a standard deviation of 0.8 years. What is the probability that a car will
2 answers:
Due to the common probability formula I can solve that task. Refering to the task you gave, we have all the information we need. We solve it like that: 
So the answer is the first option <span>0.621%</span>
So the answer is the first option <span>0.621%</span>
Standard Deviation = A = 0.8
Mean = 12 years
We will use normal distribution to calculate probability.
Let a Random variable Z , has A = 0.8, and M= 12 years.
Probability that a car will be able to last < 10 years= P(Z<10)
=
Pr (Z < -5/2) = 0.00621[ By using standard table]
= 0.00621 ×100
=0.621%→ Option A .
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I found the complete problem.
If Alice divides it into two trapezoids, the area formula would be: A = [(a+b) / 2] * h
Trapezoid 1
A = [(7.5 + 15)/2 * 5
A = (22.5/2) * 5
A = 11.25 * 5
A = 56.25 sq. ft
Trapezoid 2
A = [(5 + 10)/2 * 7.5
A = (15/2) * 7.5
A = 7.5 * 7.5
A = 56.25 sq. ft
Total area = 56.25 + 56.25 = 112.50 sq. ft.
If Alice divides it into two trapezoids, the area formula would be: A = [(a+b) / 2] * h
Trapezoid 1
A = [(7.5 + 15)/2 * 5
A = (22.5/2) * 5
A = 11.25 * 5
A = 56.25 sq. ft
Trapezoid 2
A = [(5 + 10)/2 * 7.5
A = (15/2) * 7.5
A = 7.5 * 7.5
A = 56.25 sq. ft
Total area = 56.25 + 56.25 = 112.50 sq. ft.
Answer:
And we can conclude that the true mean for the heights of mens between the ages of 18 to 24 is between 69.44 and 69.7 inches.
Step-by-step explanation:
For this case we have the following sample size n =772 from men recruits between the ages of 18 to 24
represent the sample mean for the heigth
represent the population standard deviation
We want to construct a confidence interval for the true mean and we can use the following formula:
The confidence level is 0.99 or 99%o then the significance level is and
and if we find for a critical value in the normal tandar ddistirbution who accumulates 0.005 of the area on each tail we got:
And replacing we got:
And we can conclude that the true mean for the heights of mens between the ages of 18 to 24 is between 69.44 and 69.7 inches.