How many TV's are there in your household?” was one of the

Question

questions on a questionnaire sent to 5000 people in Japan.
The collected data resulted in the following distribution:

Number of TVs/Household
0 1 2 3 4 5 or more
Percentage
1.9 31.4 23.0 24.4 13.0 6.3

One of these households is selected at random.
To find the percentages, I used the following formula:
percentile of value x =
# of values less than x
------------------------ * 100
total # of values

A) What percentage of the households have at least one TV?
31.4+23+24.4+13.0+6.3
--------------------- * 100 - 19.6%
5
B) What percentage of the households have at most 3 TV's?
1.9+31.4+23.0+24.4
------------------ * 100 =16.1%
4
My questions is: What did I do wrong and how do you solve this?

Thank you
Miss Patte

Answer 1

Work it from the other end, so you are using fewer values. You are less likely to make mistakes.

A. 100(1.00 - .019) = ?

B. 100(1.00 - .193) = ?