Answer:
21 mph
Step-by-step explanation:
The relationship between time, speed, and distance is ...
time = distance/speed
The speed downstream is b+7 if the boat's speed is b. The speed upstream is b-7, and the times in each direction are equal. This means ...
20/(b+7) = 10/(b-7) . . . . . . time in each direction are the same
20(b-7) = 10(b+7) . . . . . . . cross multiply
(20-10)b = 7(10+20) . . . . . add 7(20)-10b
b = 7(20 +10)/(20 -10) = 21 . . . . mph
The speed of the boat in still water is 21 mph.
Find the mean, median mode and range of: 75, 80, 60, 90, 85, 80, -7, 90, 70, 65
yaroslaw [1]
Answer:
Mean: 68.8.
Median: 77.5
Mode: 80, 90
Step-by-step explanation:
-7 + 60 + 65 + 70 + 75 + 80 + 80 + 85 + 90 + 90 = 688. Then divide by 10 because there are 10 numbers.
-7 + 60 + 65 + 70 + 75 + 80 + 80 + 85 + 90 + 90
(75, 80) are the middle numbers, so add them both, then divide by 2.
80, 90 appear more than the other numbers.
Range is highest - lowest. 90 - (-7) = 97, or it could be 83. I don't know.
C is correct because the first point is on 0
A) 26.7%
B) 40%
The probability of A is given by 4/6(2/5), since this is done without replacement; there are 4 blue marbles out of 6. When the first one is gone, there are 2 red out of 5 remaining.
The probability of B is given by 4/6(3/5), since this is done without replacement; there are 4 blue marbles out of 6. When the first one is gone, there are 2 blue out of 5 remaining.
Answer: The length is 6.67in and the width is 6.
