What is the first error she made in computing the variance? Emi failed to find the difference of 89 - 78 correctly.
Emi divided by N - 1 instead of N.
Emi evaluated (46 - 78)2 as -(32)2.
Emi forgot to take the square root of -135.6.

The u-drive rent-a-truck company plans to spend $13 million on 320 new vehicles. each commercial van will cost $25 comma 000, each small truck $50 comma 000, and each large truck  $80 comma 000. past experience shows that they need twice as many vans as small trucks. how many of each type of vehicle can they buy?