TODAY IN ALGEBRA…

Learning Target: 13.6 You will compare measures of central tendency and dispersion

Independent Practice

AT – Ch.9 Test corrections

13.6 MEASURES OF CENTRAL TENDENCY: MEAN, MEDIAN, MODE

MEAN:

MEDIAN:

MODE:

average

𝑆𝑢𝑚𝑜𝑓 𝑎𝑙𝑙𝑛𝑢𝑚𝑏𝑒𝑟𝑠𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑡𝑒𝑟𝑚𝑠

middle number

number that occurs the most

𝑓 𝑖𝑛𝑑 h𝑡 𝑒𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑟 𝑛𝑢𝑚𝑏𝑒𝑟𝑠 h𝑡 𝑎𝑡 h𝑠 𝑜𝑤𝑢𝑝 h𝑡 𝑒𝑚𝑜𝑠𝑡

13.6 MEASURES OF CENTRAL TENDENCY

EXAMPLE: Find the mean, median, and mode(s) of the data.

Cost (in dollars) of computer monitors:

MEAN: average

MEDIAN: middle number

MODE: most frequent number

¿296+215+426+390+351+215+289

7¿21827 ¿𝟑𝟏𝟏 .𝟕𝟏

215 ,215 ,289 ,296 ,351 ,390 ,426

𝟐𝟏𝟓

13.6 MEAN, MEDIAN, MODEEXAMPLE 2: Find the mean, median, and mode(s) of the data.

Heights (in feet) of waterfalls:

MEAN: average

MEDIAN: middle number

If there are two “middle numbers” then take the average:

MODE: most frequent number

¿1000+1000+1181+1191+1200+1268+1328+2584

8¿107528 ¿𝟏𝟑𝟒𝟒

1000 ,1000 ,1181 ,1191 ,1200 ,1268 ,1328 ,2584

𝟏𝟎𝟎𝟎¿

1191+12002

¿23912 ¿𝟏𝟏𝟗𝟓 .𝟓

13.6 MEAN, MEDIAN, MODECHECKPOINT: Complete problems Pg.877: 3-10

13.6 MEAN, MEDIAN, MODECHECKPOINT: Complete problems Pg.877: 3-10

MEAN

MEDIAN:

MODE:

MEAN

MEDIAN:

MODE:

1+1+1+2+3+3+5+5+6 9+10+12+15+169 5279

625¿𝟑 ¿𝟏𝟐 .𝟒

1 ,1 ,1 ,2 ,3 ,3 ,5 ,5 ,6 9 ,10 ,12 ,15 ,16

1 ,1 ,1 ,2 ,3 ,3 ,5 ,5 ,6 𝑁𝑂𝑁𝐸

13.6 MEAN, MEDIAN, MODECHECKPOINT: Complete problems Pg.877: 3-10

MEAN

MEDIAN:

MODE:

MEAN

MEDIAN:

MODE:

13+16+19+20+22+25+30+31 14+15+15+14+14+16+18+158 81768

1218¿𝟐𝟐 ¿𝟏𝟓 .𝟏𝟑

13 ,16 ,19 ,20 ,22 ,25 ,30 ,31 14 ,14 ,14 ,15 ,15 ,15 ,16 ,18

𝟏𝟒𝒂𝒏𝒅𝟏𝟓

20+222¿𝟐𝟏

𝑁𝑂𝑁𝐸

15+152¿𝟏𝟓

14 ,14 ,14 ,15 ,15 ,15 ,16 ,18

13.6 MEAN, MEDIAN, MODECHECKPOINT: Complete problems Pg.877: 3-10

MEAN

MEDIAN:

MODE:

MEAN

MEDIAN:

MODE:

5.52+5.44+3.60+5.76+3.80+7.22 300+320+341+348+360+3336 631.346

20026¿𝟓 .𝟐𝟐 ¿𝟑𝟑𝟑 .𝟔𝟕

3.60 ,3.80 ,5.44 ,5.52 ,5.76 ,7.22 300 ,320 ,333 ,341 ,348 ,3605.44+5.522 ¿𝟓 .𝟒𝟖

𝑁𝑂𝑁𝐸

333+3412 ¿𝟑𝟑𝟕

𝑁𝑂𝑁𝐸

13.6 MEAN, MEDIAN, MODECHECKPOINT: Complete problems Pg.877: 3-10

MEDIAN:

To use the median, you must put numbers in increasing order FIRST!MEDIAN:

13.6 MEASURES OF CENTRAL TENDENCY: RANGE

RANGE:

¿𝑔𝑟𝑒𝑎𝑡𝑒𝑠𝑡 𝑛𝑢𝑚𝑏𝑒𝑟 −𝑠𝑚𝑎𝑙𝑙𝑒𝑠𝑡𝑛𝑢𝑚𝑏𝑒𝑟

Difference of the greatest value from the least value

EXAMPLE: Top ten finishing times for the 100 meter dash and 200 meter dash are listed below. Find the range of each set of data.A:

B:

𝑟𝑎𝑛𝑔𝑒=11.32−10.62¿𝟎 .𝟕

𝑟𝑎𝑛𝑔𝑒=22.73−21.37¿𝟏 .𝟑𝟔

13.6 MEASURE OF CENTRAL TENDENCY: RANGECHECKPOINT: Complete problems Pg.877: 11-16

Find the range of the data. Round to the nearest tenth.

13.6 MEASURE OF CENTRAL TENDENCY: RANGECHECKPOINT: Complete problems Pg.877: 11-16Find the range of the data. Round to the nearest tenth.

𝑟𝑎𝑛𝑔𝑒=85−20¿𝟔𝟓

𝑟𝑎𝑛𝑔𝑒=145−111¿𝟑𝟒

𝑟𝑎𝑛𝑔𝑒=100−30¿𝟕𝟎

𝑟𝑎𝑛𝑔𝑒=550−480¿𝟕𝟎

𝑟𝑎𝑛𝑔𝑒=84.2−2.5¿𝟖𝟏 .𝟕

𝑟𝑎𝑛𝑔𝑒=1.70−0.85¿𝟎 .𝟖𝟓

EXIT TASK TO AT (unless you have test corrections)

Pg. 878: 20The population densities (in people per square mile) for each of the 10 most densely populated states in 2003 were 719.0, 418.5, 315.6, 536.6, 820.6, 1164.6, 406.5, 275.9, and 1029.9.

Find the mean, median, mode and range of the data.