Easy Middle School Math!!?

Question

Okiez,, please help me with the following questions!!

1. Brittany had test scores of 80, 85, 85, 92, and 90. If her score on the next test is 65, which measures of central tendency change?

2. While shopping, Debra estimated the sum of $48.99 and $78.85 as $130.00. How did she know that the result was an overestimate.

3. Robert's scores on six math tests are 90, 80, 80, 85, 88, and 45. How much higher is the mean of his scores without the outlier than when the outlier is included.

Please help THX!!!

Answer 1

don't know he 1st but

the second is that you rounded up so the answer must be overestimated

the 3rd. mean is average so take the scores plus each other divided by the number of scores.

good luck!

Answer 2

1)Well what are your measures of central tendency and how do you find them.  Mean is the average of the set of data: add all then numbers and divide by how many there are.  Mode is most often; which number occurs more than any.  This can have more than one answer. Median is the middle number.  Put the numbers in order from smallest to largest and then find the number in the middle.  If there are two middle numbers find the average of those two numbers. Lastly range is where you take the largest number and subtract the smallest number.



First look at your measures without the next test score.

mean 86.4

mode 85

range 12

median 85

Then look at your measures with the next test score.

mean 82.3

mode 85

range 27

median 85

Now you can tell which ones changed.

2) Well you know that $130.00 is $80 + $50.  She knows that she rounded both prices up so she added to it making that rounded total larger than the actual.

3)We do the mean the same way in this question as in the first.  Now you must know what an outlier is.  That is the one thing that stands out. With numbers it is the one that is not close to the other numbers.  In this set of data 45 is the outlier.  Now just find the mean with and without the outlier.

Mean with 78

Mean without 84.6

Then just subtract the two numbers and you will find out how much higher the one is.