Answer:
The standard deviation of car age is 2.17 years.
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 7.5
(a) If 99.7% of the ages are between 1 year and 14 years, what is the standard deviation of car age?
This means that 1 is 3 standard deviations below the mean and 14 is 3 standard deviations above the mean.
So

I want to find 



The standard deviation of car age is 2.17 years.
Animal shelter in Austin is a dog is 11.71% and <span>a randomly selected orphaned dog in the same animal shelter in Austin is a Chihuahua is</span> 29.38%.
Solve for x.
(3x+1)2-100=0
(3x+1)2=100
3x+1=100/2
3x=50-1
x=49/3
x=16.33333
Hope that helps. If you have any other questions feel free to ask me