I think the answer maybe be 10 miles. If he rowed upstream, that is four, and it took only one hour. Downstream he went 6 mph. We dont know how long he spent each way, so it might be cut evenly in half. Saying he spent one hour too and fro, the answer would be ten because all we have to do is add 4 and 6. This may be completely wrong, but there isn’t that much context.
Answer: Scalane acute
Step-by-step explanation:
Answer:
B.5/7 and C.20/28
Step-by-step explanation:

5:7
Answer:
It is a discrete distribution of probability, with mean = 0.879 and SD = 0.787.
Step-by-step explanation:
With the given data, it can be said we have a discrete distribution of probability.
Calculation of the mean

Calculation of the standard deviation

OK, you need to distribute the x. Think of it as spreading it out into the parentheses.
(y-2)x becomes xy-2x
Just to show you another one so you get the concept.
If you had 3(x+5+y) it becomes 3x+15+3y. You spread the 3 out to multiply it by everything in the parentheses.
If that does not make sense feel free to ask me because this concept will come up again and again.
Hope that helps.