91Ó°ÊÓ

For a $t-$curve with $\mathrm{df}=8$

The degrees of freedom of the $t-$curve is 8

We have to obtain the $t-$value having area $0.05$to its right i.e. to obtain $t_{0.05}$for $df=8$

$∴$For $df=8,t_{0.05}=1.860$[From table IV of APPENDIX $-\mathrm{A}$]

Create the Graph plot

We have to obtain $t_{0.10}$ for $df=8$ For $df=8,t_{0.10}=1.397$

We have to obtain $t-$value having area $0.01$to its left.

$t-$Curve is symmetric about 0 . So, $t-$value having area $0.01$to its left is equal to the negative of the $t-$value having area $0.01$to its right.

$∴$With $df=8,t$- value having area $0.01$to its left $=-t_{0.01}$

Create the Graph plot

We must acquire the two $t-$values that divide the area under the curve into a $0.95$ area in the middle and two $0.025$ areas on either side.

i.e. We have to obtain $-t_{0.025}$and $t_{0.025}$for $df=8$

$[âˆ\mu t$-curve is symmetric about $0$]

From table IV,

For $df=8,t_{0.025}=2.306$

$∴$The required two $t-$values are $-2.306$and $2.306$

Create the Graph plot