Using it's concept, it is found the standard deviation of $10 means that most students spent within $10 of the mean of $60 on the slot machines.
<h3>What is the standard deviation of a data-set?</h3>
The standard deviation is given by the square root of the sum of the differences squared of each observation and the mean, divided by the one less than the number of values.
It represents by around how much the distribution varies around the mean.
Hence, in this problem, the standard deviation of $10 means that most students spent within $10 of the mean of $60 on the slot machines.
find the missing length of the triangle using Pythagoras then use this value (8) to find the surface area of the sides and the triangle.Add up the values.