Answer:
18km/h
Step-by-step explanation:
if the riverboat is already going 15 km/h and the current is 3km/h then you should add and you get 18 km/h
Missing question: How many executives should be surveyed?
Solution:
Mean = 13 hours
SD = 3 hours
Confidence level = 95%
Mean viewing time within a quarter of an hour = 0.25 = 1.96*3/sqrt (N)
Where N = Sample population
N = {(1.96*3)/0.25}^2 = 553.19 ≈ 554
Therefore, 554 executives should be surveyed to yield such results.
The probability is a ratio of the possible events to the total events. The total is 52 cards, so the denominator is 52. The individual properties of the specific cards are the following:
Any face or number cards is 4/52, because there are 4 cards for each symbol. On the other hand, each symbol like heart, diamond, club or spade would each have a probability of 13/52 (counting numbers 2 to 10, Ace card, and the 3 face cards). Also, there are 26 each of red and black cards. Furthermore, the words 'or' and 'and' are hint words. When you see 'or', you have to add their individual probabilities. If you see the word 'and', you'll have to multiply them. With that said, the solution is as follows:
a.) P = 4/52 + 4/52 + 4/52 = 3/13
b.) P = (13/52 + 13/52 + 4/52)(26/52) = 15/52
c.) P = 13/52
d.) P = 13/52 + 13/52 + 13/52 = 3/4