I'm guessing the answer is B? I tried to isolate r and I got that result. Sorry if it's wrong!
Answer:
0.1151 = 11.51% probability of completing the project over 20 days.
Step-by-step explanation:
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the z-score of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Expected completion time of the project = 22 days.
Variance of project completion time = 2.77
This means that 
What is the probability of completing the project over 20 days?
This is the p-value of Z when X = 20, so:



has a p-value of 0.1151.
0.1151 = 11.51% probability of completing the project over 20 days.
It could’ve been higher or lower for the cost of kilobyte of data. That is the answer because there isn’t no information or a picture of the question.
Hope this helps :)
1. 672/12 = 56
2. 1440/16 = 90
3. 784/7 = 112
Use pythagorean theorem. 11m is the hypotenuse, while 4m is one of the legs. the wall should create a right angle with the ground which will allow for the pythagorean theorem. The height of where the ladder reaches will be named x.
x=<span>√11^2-4^2=10.25m.</span>