Derrick needs to figure out how he’s doing on his test scores so far this year. You can help by calculating the mean and the median to get an overall picture of his scores. Below are all of his scores: 25, 40, 68, 85, 95, 98, 70, 78, 85, 100

Mean = 74.4

Median = 81.5

Step-by-step explanation:

25, 40, 68, 85, 95, 98, 70, 78, 85, 100

Mean = Sum of values / Number of values

Number of values = 10

= 25 + 40 + 68 + 70 + 78 + 85 + 85 + 95 + 98 + 100/10

= 744/10

= 74.4

Median

Rearranging the given data

= 25, 40 ,68 ,70 ,78 ,85 ,85 , 95 ,98 ,100

Formula for median = 1/2(n + 1)th value

n = 10

Hence

1/2(10 + 1)th value

1/2(11)th value

= 5.5 th value

This fall between the 5th and 6th value

5th value = 78

6th value = 85

Hence: 78 + 85/2

= 163 / 2

= 81.5

goog may have it for you

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.