Answer:
c) at most 11.1%
Step-by-step explanation:
We have the data that is 97 ± 12, with 97 being the mean and 12 the standard deviation.
Now, the percentage of people who reached them for less than 73 dollars, if it were a normal distribution:
z = (73 - 97) / 12 = - 2
so it would be, a probability of 0.0228 or 0.228%.
But we don't know what distribution it has, but we can get an idea.
A and D discarded, as they are very high values, and 73 is well below the average.
B) is still a very high value.
Therefore the answer is C, at most 11.1%
Let x = the number of hours Eva needs to complete the job
and y = the number of hours Emily needs to complete the job
x = 6
1/x + 1/y = 1/4
(The amount of work Eva does in 1 hr + the amount of work Emily does in 1 hr should equal 1/4 of the total work)
1/6 + 1/y = 1/4
1/y = 1/12
y = 12 hours
Emily would take 12 hours to do it by herself.
