Answer:
- boat speed: 17.25 mph
- current: 2.5 mph
Step-by-step explanation:
Upstream, the speed of the current (c) subtracts from the speed of the boat (b) to give the net speed. Downstream, the speed of the current adds. We can make use of the relation ...
speed = distance/time
b-c = 29.5/2 = 14.75 . . . . . miles/hour
b+c = 59.25/3 = 19.75 . . . .miles/hour
Subtracting the first equation from the second, we get ...
(b+c) -(b-c) = 19.75 -14.75
2c = 5
c = 2.5
Then either equation can be used to find b:
b = 14.75 +c = 17.25
The speed of the boat in still water is 17.25 miles per hour; the speed of the current is 2.5 miles per hour.
The girl will have walked 20,000 meters or 20 km
A 99% confidence interval will be wider compared to a 95% confidence interval. This is because while you don't know what the true value of mu is, you are more confident that the parameter is in the interval.
In essence, you are casting a wider net which leads to the higher level of confidence. Imagine if there was a 100 mile stretch of straight land, and somewhere on this line was a special rock that you are looking for. You would be 100% confident if you said "the rock is somewhere on that piece of land", and less confident the more you shrunk the interval.
I think it would be 4.
8 breaks down to 4(2) and 12 breaks down to 4(3). Let me know if that helps!
