I suck at math and can't understand this foreign talk. Can someone explain.?
1. A lawyer bills her clients 0 per hour of service. If a client’s case requires 17 hours to complete, use a proportion to calculate how much the client will owe the lawyer (excluding tax).
2. A new virus is released on the internet; the administrator of a department’s Local Area Network (LAN) is given five minutes by a manager to estimate the impact. The administrator samples 12 of the PCs connected to the LAN and finds that 7 are infected. Use a proportion to estimate the number of infected PCs if there are a total of 216 PCs connected to the LAN.
3. An administrator of a popular web site is told that a new faster server, which will replace the old server, can handle 45,000 "hits" (users accessing the site) per second. The web site currently experiences a peak demand of about 110,000 hits per second. But, every month, the peak demand increases by 2500 hits per second. Use a proportion equation to determine how many new servers the administrator should buy to address expected traffic for the next 24 months.
One Response
Patti
25 Feb 2010
A proportion or ratio describes a "numerical" relationship between two items. For example: $300 fee per 1 hour of attorney time, or of 12 PC’s tested for a virus, 7 were infected. You write these relationship like a fraction: 300/1 and 12/7 respectively.
So in the first problem, your would set up two fractions, the second with an unknown that you have to solve for.
$300/ 1 hours = $?/17 Hours (notice you keep the same type of item in the same place for each fraction… In this case $ go on top in the numerator and Hours go on the bottom (denominator).
To solve a proportion you "cross multiply" so that 17×300=1 x $?? So the answer is $5,100.
In the second problem 12 total computers sampled/7 infected = 216 computers on the LAN/? infected. 12?=1512 1512 divided by 12 is 126. So there are 126 infected computers on the entire LAN.
See if you can apply this to the last problem.