The National Oceanographic and Atmospheric Association (NOAA) has provided data for global temperature changes from the 20th century average temperature of 13.9ᵒC. The temperature changes are given with the number of years in two separate frequency tables below. Table I Table 2

50 Years from 1901 – 1950 49 Years from 1968-2017

(No Data from 2005)

ᵒC change

Frequency

(# years)

ᵒC change

Frequency

(# years)

-0.4

6

-0.1

3

-0.3

9

0.0

4

-0.2

12

0.1

3

-0.1

12

0.2

6

0.0

5

0.3

8

0.1

1

0.4

8

0.2

4

0.5

3

0.3

1

0.6

8

0.4

0

0.7

3

0.5

0

0.8

1

0.6

0

0.9

2

1. Find a weighted mean for the ᵒC change from the data in the first table, 1901 through 1950, by multiplying the ᵒC change amount by the frequency, then totaling the results for Table 1 and dividing by the total number of years, 50, for the first table. You now have a weighted mean change for Table 1.