Step-by-step explanation
For the first part
When P=89%
P=0.89
This means that 89% of the data lies within at least 3 standard deviations
This will be between
Part B
Part C
If we are to use the empirical rule
The empirical rule, also referred to as the three-sigma rule or 68-95-99.7 rule, is a statistical rule which states that for a normal distribution
Then since the standard deviation is 6.00
120mmHg and 144mmHg are within 2 standard deviations
This is within 2 standard deviations
Thus
we have the answer as 95%
Part D
68% of the measurement will be between 126mmHg and 138mmHg