Answer:
a) 0.05
b) 0.9826
c) 0.000039308
Step-by-step explanation:
a) 
b) For two minutes, the mean is doubled, hence it is 6. In order to calculate the probability of al least two calls arriving, we calculate first the probability of the complementary event: At most 1 call will arrive. For that probability, we need to sum the probabilities of 0 and 1.


Hence,

c) For five minutes the mean is 15. We need to sum the probabilities of 0, 1 and 2.


As a result,

Practically 0
IN finding the interest we need to use the following formula:
Interest= Principal x Rate x Time or I= PRT
Substitute values: I= [$20 + ($10 x $34)] -320 =$40
P= $320
R=?
T=10 months/year
I=PRT
Since R is a missing term, we will solve for R using this formula: R=I/PT
R= [<span>$20 + ($10 x $34)-320] / ($320 x 10 months)
T=10 months</span>÷12 months=0.83<span>
R= ($40)/ $320 X 0.83
R= 40/ 265.6
R=15.06024096</span>
Answer:
0.3114
Option d is right
Step-by-step explanation:
Let X be the time spent on a treadmill in the health club
Given that research shows that on average, patrons spend an average of 42.5 minutes on the treadmill, with a standard deviation of 5.4 minutes
Also given that X is normal
the probability that randomly selected individual would spent between 30 and 40 minutes on the treadmill.

round off to two decimals tog et
the probability that randomly selected individual would spent between 30 and 40 minutes on the treadmill is 0.31
Hence option d is right
Answer:
2.5 hours
Step-by-step explanation:
The product of speed and time is distance. If the distance is the same, then time is inversely proportional to speed. At 60/50 = 6/5 times the speed, the return trip will take 5/6 times the time:
(5/6)(3 hours) = 2.5 hours . . . time for return trip