Problem No$.1$

Three mortar mixes with water$-$to$-$cement ratios of $0\mathrm{.}45,0\mathrm{.}50,$ and $0\mathrm{.}65$ were prepared. Three $50-mm$ mortar cubes were cast for each mix. The cubes were cured for $7$ days and then tested for compressive strength. The test results are shown in the table. Determine the following.

a$)$ The compressive strength of each cube

b$)$ The average compressive strength for each mix

c$)$ The standard deviation of the compressive strengths measured for each mix

d$)$ Plot the average compressive strength versus watercement ratios for all mixes

e$)$ Comment on the effect of increasing the watercement ratio on the compressive strength of the

$\backslash$table$[[$w$/$c$,\backslash$table$[[$Max$.],[$Load$],[(kN)$