Answer: 0.1052
Step-by-step explanation:
Given : Mean :[tex]\mu= 120[/tex]
Standard deviation : [tex]\sigma= 5.6[/tex]
We assume the variable is normally distributed.
The formula for z-score is given by :-
[tex]z=\dfrac{x-\mu}{\sigma}[/tex]
For x=120.4
[tex]z=\dfrac{120.4-120}{5.6}=0.0714285714286\approx0.07[/tex]
For x=121.9
[tex]z=\dfrac{121.9-120}{5.6}=0.339285714286\approx0.34[/tex]
The p-value =[tex]P(0.07<z<0.34)=P(0.34)-P(0.07)[/tex]
[tex]=0.6330717-0.5279031=0.1051686\approx0.1052[/tex]
The probability that the individual's pressure will be between 120.4 and 121.9 mm Hg = 0.1052