Algebra Discussion, Statistics Problem Example

Part 1 Solution

Car selected: BMW 128i

“www.fueleeconomy.gov” describes as BMW 128i is 28 mpg
suppose y is the number of miles driven on 60 gallons of gas.
Then we have
y/28 = 60/1
by multiplying both sides by 28 we obligate
y =60*28 = 1680 miles.
Therefore the number of miles driven on 60 gallons of gas is 1680.

Part 2 Solution

We have to square both sides initially: D^2 = 2 h.
dimensions: [LHS] = L^2 <> [RHS] = L
using LHS will be used for left had side and RHS will be used for right hand side, <> for is not equal to, L for length
units: [LHS] = ft^2 <> [RHS] = ft

Height: h = 100 ft (about 10 stories)
According to Wikipedia radius of Earth: R = 3960 mi = 3960 mi * 5280 ft/mi = 2.091*10^7 ft
The precise equation is Distance to horizon: D = sqrt( 2 R h )
D = sqrt( 2 * 3960 mi * 5280 ft/mi * 100 ft) = 64666 ft / (5280 ft/mi) = 12.25 mi

References

2009 Vehicles from BMW. Gas Mileage of 2009 Vehicles. Retrieved May 12, 2010, from http://www.fueleconomy.gov/feg/bymake/BMW2009.shtml

(2010, May 11). Earth Radius. Wikipedia “The free Encyclopedia”. Retrieved May 12, 2010, from http://en.wikipedia.org/wiki/Earth_radius