Question 559471
<pre>
mean = (number)×(probability)

mean = 400×{{{1/10}}} = 40

variance = (number)×(probability)×(One minus probability)

variance = (400)×(1/10)×(1-{{{1/10}}}) = (400)×({{{1/10}}})×({{{10/10}}}-{{{1/10}}}) = (400)×({{{1/10}}})×({{{9/10}}}) = 40×{{{9/10}}} = {{{360/10}}} = 36

Edwin</pre>