He pays $135 for 3 years. So that’s $45/year. Considering 900 is your 100%, how many percents are represented by $45 in 900?
1)
You can see that 900 = 9x100.
So you can divide 900 by 9 to get 100.
That means you can also divide 45 by 9 (it’s proportional)
You have 45 for 900, you divide by 9 so you get 5 for 100 -> 5%
Or 2)
(Photo)
It’s a cross-multiplication :
(45 x 100)/900 = 5%
So the interest rate is 5%.
(Sorry if it’s confusing, English isn’t my first language..)
Understand the problem
Gather your resources
Come to an answering
Check your answer and present the solution
Answer:
And we can find this probability using the complement rule and the normal standard table or excel:
The firgure attached illustrate the problem
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the retirement savings of a population, and for this case we know the distribution for X is given by:
Where 
and 
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability using the complement rule and the normal standard table or excel:
The firgure attached illustrate the problem
Answer:
-2
Step-by-step explanation:
Hope It Helps
The answer would be 483,972 miles = 55
