Complete Question
Find the indicated area under the curve of the standard normal distribution, then convert it to a percentage and fill in the blank.
About_____% of the area is between z = - 2.2 and z = 2.2 (or within 2.2 standard deviations of the mean).
About_____% of the area is between z = - 2.2 and z = 2.2 (or within 2.2 standard deviations of the mean).
Answer:
About 97.219% of the area is between z = - 2.2 and z = 2.2 (or within 2.2 standard deviations of the mean).
Step-by-step explanation:
From the question given we can see that they both are the same so 1 will just solve one
Now the area under this given range can be represented mathematically as
[tex]P ( -2.2 < z < 2.2) = P(z < 2.2 ) - P(z < -2.2 )[/tex]
Now from the z-table
[tex]p(z < 2.2 ) = 0.9861[/tex]
and
[tex]p(z < - 2.2 ) = 0.013903[/tex]
So
[tex]P ( -2.2 < z < 2.2) = 0.9861 - 0.013903[/tex]
[tex]P ( -2.2 < z < 2.2) = 0.97219[/tex]
So converting to percentage
[tex]P ( -2.2 < z < 2.2) = 0.97219 * 100[/tex]
[tex]P ( -2.2 < z < 2.2) = 97.219 \%[/tex]
