Problem $3.$ Consider the time history of pressure changes in a manifold carrying a fluid,

extracted from an experimental test, tabulated as below:

Determine the pressure change with respect to time $(d\frac{P}{d}t)$ at $t=1\mathrm{.}25s$ using: $($a$)$ Forward

finite$-$divided difference $($b$)$ Backward finite$-$divided difference, and $($c$)$ Centered finite$-$divided

difference. Tabulate your results to compare them.