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gogolik [260]
3 years ago
14

A boat traveled 225 miles each way downstream and back. The trip downstream took 9 hours. The trip back took 15 hours. What is t

he speed of the boat in still water? What is the speed of the current?
Mathematics
1 answer:
Karolina [17]3 years ago
5 0

Answer:

Boat = 20 mph

Current = 5 mph

Step-by-step explanation:

If b is the speed of the boat, and c is the speed of the current, then:

b + c = 225 / 9 = 25

b − c = 225 / 15 = 15

Solve the system of equations with elimination.

2b = 40

b = 20

Plug back into either equation to find the speed of the current.

c = 5

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svetlana [45]

Answer:

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Step-by-step explanation:

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The upper end of the interval is the sample mean added to M. So it is 9.8 + 0.2 = 10 reproductions per hour.

The 99% confidence interval for the true mean number of reproductions per hour for the bacteria is between 9.6 and 10.

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