The following consecutive readings were taken with a dumpy level: $1\mathrm{.}893,$

$1\mathrm{.}500,1\mathrm{.}865,2\mathrm{.}566,2\mathrm{.}990,2\mathrm{.}021,2\mathrm{.}411,2\mathrm{.}518,2\mathrm{.}960$ m$.$ The level was

shifted after $4$th and $6$th readings. The reduced level at the first point was

$100\mathrm{.}000$ m$.$ Enter the readings in the form of level book and reduce the

level by the collimation method and apply the arithmetical check. Find the

gradient between the first and last stations