Assume the weight distribution has a normal distribution with an average of $160$ lbs and a SD of $20$ lbs$.$ What portion of the weights are above $145$ lbs$?$

Group of answer choices

Less than $0\mathrm{.}2420$

$0\mathrm{.}2420$

$0\mathrm{.}2266$

$0\mathrm{.}7881$

$0\mathrm{.}7580$

$0\mathrm{.}7734$

More than $0\mathrm{.}7734$