Complete Question
The complete question is shown on the first uploaded image
Answer:
The calcium level that is the borderline between low calcium levels and those not considered low is 
Step-by-step explanation:
From the question we are told that
The mean is 
The standard deviation 
The proportion of the population with low calcium level is
5% = 0.05
Let X be a X random calcium level
Now the P(X < c) = 0.05
Here P denotes probability
c is population with calcium level at the borderline
Since the calcium level is normally distributed the z-value is evaluated as

The critical value for 0.05 from the standard normal distribution table is

=> 
substituting values

=> 
=> 
I need a lil more information
Very simple, we don’t know the units on the graph but I can tell you it will be linear until when it breaks the rule and goes .2 grams one year
5/6 of a number cannot be greater than the number