Two faces of a slab are maintained at two different temperatures, T$1>$ T$2.$ All other faces are perfectly

insulated, so heat can flow only along x$-$direction. Temperatures are measured at five different

locations along the width, L$,$ of the slab, as shown in the table.

Using LINEST function of Microsoft Excel, perform a linear regression of T on x$.$ What is the lower

bound of the interval estimate for temperature at $x=78mm?$

In your calculations, use the values returned by Excel preserving all the decimal places as returned by

Excel.

Write your final answer in decimal form with two digits to the right of the decimal point $($e$.$g$.5\mathrm{.}32)$; do

not write any units or sign.

Note: You may use Microsoft Excel application during your test to work on this problem.