Answer:
12
Step-by-step explanation:
if the line is 18 inches long and a 1.5 space apart then u divide them and 18 divided by 1.5 is 12
B, -3x+15=23 is the answer
10 -3.5 and 10 -8.5 is the answer I think
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

=> 
=> 