91影视

Given that the question is:

$z鈮�鈭�2.25$

In the graph below, the given region is shown as follows:

The number below $-2.25$ is $0.0122$, according to the conventional normal table.

Given that the question is:

$z鈮�鈭�2.25$

The region in question is seen in the graph below.

Part (a) shows that the region below $-2.25$is $0.0122$.

The fraction of observations greater than $-2.25$is then computed.

$=$Total Proportion$-$proportion of observations before $-2.25$

$$\begin{gathered} =1-0.0122 \\ =0.9878 \end{gathered}$$

Given that the question is:

$z>1.77$

The region in question is seen in the graph below.

The area before $1.77$is $0.9616$using Standard Normal tables. As a result, $0.9616$is the fraction of observations below $1.77$.

The proportion of observations larger than $1.77$is then calculated by subtracting the value of the proportion less than $1.77$from $1$(total proportion).

$$\begin{gathered} 1-0.9616=0.0384 \\ =3.84\% \end{gathered}$$

Given that the question is:

$鈭�2.25<z<1.77$

The region in question is seen in the graph below.

Subtract the area before $-2.25$from the area before $1.77$to get the needed region.

The area before $-2.25$is $0.0122$, as calculated from component (a). Also, $0.9616$is the region preceding $1.77$. (from Standard Normal tables)

Then there's the region between $-2.25$and $1.77$.

$$\begin{gathered} 0.9616-0.0122=0.9494 \\ =94.94\% \end{gathered}$$