Averages “Average” when you stop to think of it is a funny concept. Although it describes all of...

Averages “Average” when you stop to think of it is a funny concept. Although it describes all of us it describes none of us. While none of us wants to be the average, we all want to know about him or her. 1.3 Describing Data Find an average for each of the following. a) Bo’s test scores 94, 87, 90, 84, 82, 91 b) sizes of Nike Air Max sold 9, 9, 9, 12, 11, 8, 6, 9, 9, 10, 7, 6, 9 c) cost of homes 125 000, 122 000, 250 000, 120 000, 121 500

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Transcript of Averages “Average” when you stop to think of it is a funny concept. Although it describes all of...

Averages“Average” when you stop to think of it is a funny concept.

Although it describes all of us it describes none of us. While none of us wants to be the average, we all want to

know about him or her.

1.3 Describing Data

Find an average for each of the following.a) Bo’s test scores

94, 87, 90, 84, 82, 91b) sizes of Nike Air Max sold

9, 9, 9, 12, 11, 8, 6, 9, 9, 10, 7, 6, 9c) cost of homes

125 000, 122 000, 250 000, 120 000, 121 500

Page 2: Averages “Average” when you stop to think of it is a funny concept. Although it describes all of us it describes none of us. While none of us wants to.

The average person is sick in bed seven days a year missing five days of work.

The average man is five feet, nine inches tall; the average woman is five feet 3 inches.

By his or her 70 th birthday, the average person will have eaten 14 steers, 1050 chickens, 3.5 lambs, 25.2 hogs.

Page 3: Averages “Average” when you stop to think of it is a funny concept. Although it describes all of us it describes none of us. While none of us wants to.

• What is an average?

average- a number that describes/represents a set of numbers

– a number that is typical of a set

-averages are also referred to as measures of central tendency

Page 4: Averages “Average” when you stop to think of it is a funny concept. Although it describes all of us it describes none of us. While none of us wants to.

• mean – the sum of the data divided by the number of data values. ex. 11, 9, 7 11+ 9 + 7 = 27 27 / 3 = 9

• median – the middle piece of data - arrange the data in order and find the middle # - if there are an even number of data values, the median is the mean of the middle two ex. a) 2, 4, 5, 6, 10 median = 5 b) 9, 10, 11, 12 10 + 11 = 21 21 / 2 = 10.5

• mode – the number that occurs the most ex. 4, 4, 2, 1, 3, 4, 4, 5 mode = 4 -there can be one, more than one or no mode

Page 5: Averages “Average” when you stop to think of it is a funny concept. Although it describes all of us it describes none of us. While none of us wants to.

Find the mean, median and mode for a – c

a) mean = 88 b) mean = 8.8 c) mean = 147700

median = 88.5 median = 9 median = 122000

mode = n/a mode = 9 mode = n/a

• Suggest which average you feel best describes the data in a – c and/or why one of the averages isn’t good.

Page 6: Averages “Average” when you stop to think of it is a funny concept. Although it describes all of us it describes none of us. While none of us wants to.

• Find the three averages for each of the following situations. Tell which you feel best describes the data and why. a) # of cups of coffee bought 1, 1, 1, 0, 2, 3, 1, 1, 4, 1, 1 b) players weights 201, 204, 208, 105, 210 c) snowfall per day 1.4, 2.6, 4, 7, 3.8, 5.5, 1.8

a) mean = 1.45 b) mean = 185.4 c) mean = 3.7 median = 1 median = 204 median = 3.8 mode = 1 mode = n/a mode = n/a