The rate a computer works is 1/time. Working together, you add the rates.
Let new computer be x, old computer be y.
x = y - 7
Rounded to nearest tenth gives:
x = 23 hours
You can find the slope and y-intercept, and make an equation in slope- intercept form and them just plug in the other x values in the equation.
When adding/subtracting fractions you need a common denominator, but you already have one, which is x-3. So in general:
a/c-b/c=(a-b)/c so you just have:
(2x-6)/(x-3) now if you factor 2 from the numerator
2(x-3)/(x-3) the (x-3)s cancel out leaving
2
However! Note that division by zero is undefined, so x cannot equal 3. (because both original fractions had denominators of x-3)
What this all means is that that expression will equal 2 for all real values of x other than 3.
Step-by-step explanation:
Margin of error = critical value × standard error
ME = CV × SE
At 95% confidence and 20 degrees of freedom, CV = 2.086.
SE = s / √n
SE = 0.16 / √21
SE = 0.035
So the margin of error is:
ME = 2.086 × 0.035
ME = 0.073
