Remove a number from the following data set so the mean is 20.
10, 12, 20, 23, 25

Take £ to be sigma

mean=£fx/£f

This means the sum of the digits divided by the number of digits

So from the above question 10+12+20+23+25=90 but 90 - 10 = 80

And 80 divided by 4 is 20

therefore the mean is 20.

Step-by-step explanation:

First of all, since the sum of the above digits is 90, we would need to exclude one of the above digits to make the number, a number divisible by 4( since we have excluded one of the 5 digits to make it 4 ) equal to 20.

So systematically, the equation would be defined as

x/4 = 20/1

hence we cross multiply and x becomes

x = 20 × 4

therefore x= 80

Hence, since x = 80 we divide this by our number of digits above hence giving you

80 ÷ 4 = 20

So from the above equation, we would need to exclude 10 to give us our mean of 20.

δabc ≅ δdcb by sas because

db ≅ ac . . given (side)

bc ≅ bc . . reflexive property (side)

∠dbc ≅ ∠ acb . . alternate interior angles where transversal bc crosses parallel lines bd and ac (included angle)