Question

You test 8 automobiles and find that their mileage ratings are 28, 28, 29, 30, 33, 34, 35, and 340 mpg, arranged in order from smallest to largest. The average of these numbers is 557 ÷ 8, or 70 mpg. However, the last data value (340 mpg) seems impossibly large, and you decide that it must be due to an error in the data gathering process.

Answer 1

Rather than doing all your measurements all over again, at considerable expense, you decide to simply ignore the "bad" value of 340 mpg. (When they do this, scientists say they are "rejecting the outliers," by ignoring unreasonable values that are nowhere close to the main cluster of data points. This procedure has some risks.) What is the mean of the remaining mileage numbers?

Answer 2

sorry all one question

Answer 3

what i did was (557-340)/7

Answer 4

and got 31

Answer 5

that´s correct

Answer 6

\[ \frac{28+28+ 29+ 30+ 33+ 34+ 35}{7}\]

Answer 7

donkey work, i would cheat
http://www.wolframalpha.com/input/?i=mean++28%2C+28%2C+29%2C+30%2C+33%2C+34%2C+35

Answer 8

but then you wouldent learn anything ;p

Answer 9

what do you learn by punching buttons on a calculator?
or moving beads on an abacus?

Answer 10

beads on an abacus of course haha

Answer 11

i know you added up in your head, and then divided by 7
ok
but my slide rule is rusty, so i used stones

Answer 12

what @summertimesadness proposed as solution is no donkey work and much more reasonable than yours @satellite73

Answer 13

ohh that sounds so much more efficient @satellite73 haha

Answer 14

the sum and the outlier are given data, so no need to add the remaining seven

Answer 15

ohh yeah huh