Answer:
The answer is "78.25%"
Step-by-step explanation:
Given:
[tex]\mu =20\\\\\sigma=1.4[/tex]
[tex]p(18.48<x<22.63)=p(\frac{18.48-20}{1.7}<\frac{\bar{x}-\mu}{\sigma}<\frac{22.63-20}{1.4})\\\\[/tex]
[tex]=p(\frac{-1.52}{1.7}<Z<\frac{2.63}{1.4})\\\\=p(-0.89<Z<1.87)\\\\[/tex]
[tex]=p(Z<1.87)-p(Z<-0.89)\\\\[/tex]
[tex]=0.969258-0.1867329\\\\=0.7825251\\\\=78.25 \%[/tex]