Currently, the standard deviation is 10, because on average the cards were $10 away from the mean.
Adding another card with value $25 would decrease the standard deviation because it is closer to the mean the the current standard deviation.
X, 2x, and (x+2x)=3x
6x=180
x=30
30, 60, 90 triangle.
Answer:
Marta can swim a lap 0.7 or seconds faster than Jessica
I don't exactly know how to explain step 2 but the working is:
5 - 8x < 2x + 3
5 - 3 < 2x + 8x
2 < 10x
5 < x
(I'm sorry if it's wrong)
Triangle abc i guess
I don't rlly understand what you mean
