Hello, 6Brandon6!

They are talking about Accuracy and Rounding.

1. The weights of four rowers are 86.3 kg, 89.2 kg, 85.0 kg and 93.9 kg.

a) Find the upper limit of their total weight

We assume they rounded the weights to the nearest tenth of a kilogram.

The weight of Rower #1 was given as kg.

His actual weight must beless thankg.

If his weight was exactly , it would have been roundedupto kg.

. . So we have: .[1]

The weight of Rower #2 was given as kg.

. . So we have: .[2]

The weight of Rower #3 was given as kg.

. . So we have: .[3]

The weight of Rower #4 was given as kg.

. . So we have: .[4]

Adding[1],[2],[3],[4], we have: . kg.

Therefore, the upper limit of their total weight is kg.

b) Use the answer to a) to find the maximum value of the mean weight

We have: .

Therefore, the maximum value of their mean (average) weight is: kg.

c) Find the minimum value of the mean weight.

The weight of Rower #1 was given as kg.

His actual weight must begreater than or equal tokg.

If his weight was less than , it would have been roundeddownto

. . So we have:\ .

. . . . Similarly: .

Hence: .

Therefore, the minimum value for their mean weight is: . kg.