Answer:
- boat: 16 mph
- current: 4 mph
Step-by-step explanation:
speed = distance / time
The rate downriver is (60 mi)/(3 h) = 20 mi/h.
The rate upriver is (60 mi)/(5 h) = 12 mi/h.
The rate of the boat in still water is the average of these:
(20 +12)/2 mi/h = 16 mi/h
The rate of the current is the difference between the boat speed and actual speed:
16 mi/h - 12 mi/h = 4 mi/h
1,5 one and a half cups of blueberry jam
Answer:
2.42
Step-by-step explanation:
standard deviation= sqrt(variance)
Variance=E[X2] - E[X]2
E[X] = sum(X)/n=35/9, so E[X]2 = 1225/81
E[X2] =sum(X2)/n = 189/9 = 170/81
Variance= 476/81
Standard deviation = sqrt(476/81) ~2.42
If you are talking about $110 being increased by 140% then the answer is $264