Hi there! The answer is 5/6 hours (which is 50 minutes)
To find the total time Ann spent on her papers, we must add the fractions.

In the first step, we had to make the denominators the same. We need to use the LCM of the numbers 2 and 3. LCM(2,3) = 6.
In the second step we added the fractions. Remember that we only need to add the numerators (the denominator remains the same).
~ Hope this helps you!
The answer is -86. Solve by dividing(344/-4).
Answer:
Z = (60 - x + y + z) / √a + b + c
Step-by-step explanation:
Since it is a normal distribution, we must calculate the mean and standard deviation, since we do not have data, what we will do is leave them based on these:
Thus Total Mean time = M1 + M2 + M3
given:
M1 = x
M2 = y
M3 = z
Total Mean Time M = x + y + z
Now to calculate the standard deviation we first calculate the variance.
The total Variance V = V1 + V2 + V3
Given:
V1 = a
V2 = b
V3 = c
V = a + b + c
Thus Standard deviation SD of the complete operation is
SD = √ V
SD = √a + b + c
we need to find the probability that the mean time is less than or equal to 60 minutes, the first thing is to find the value of Z.
Formula of Z is:
Z = (X - M) / SD
In this case X = 60.
On plugging the values we get
Z = (60 - x + y + z) / √a + b + c
refer to the Z table and find the Probability of Z ≤ (60 - x + y + z) / √a + b + c