Let r be the decay rate (time in minutes) 17 = 20 e^(5r) 0.85 = e^(5r) ln 0.85 = 5r similarly, ln 0.5 = hr ... where h is the half-life, so dividing the 2 equations, ln 0.85 / ln 0.50 = 5r / hr = 5/h h = 5 ln 0.50 / ln 0.85 h = 21.3 min b) 1/20 = 0.05, so ln 0.85 = 5r ln 0.05 = tr t = 5 ln 0.05 / ln 0.85 t = 92.2 min
Answer:
$0.25 per ounce
Step-by-step explanation:
3.75 divided by 15 is 0.25
Answer:
The estimate for the proportion of Americans over 33 who smoke is 0.28.
Step-by-step explanation:
Proportion of Americans over 33 who smoke.
Number who smoke divided by the size of the sample.
In this question:
Sample of 1267.
913 don't smoke, so 1267 - 913 = 354 smoke. Then
The estimate for the proportion of Americans over 33 who smoke is 0.28.
Answer:
16-2n=-8+4n-12
16+8+12=4n
36/4=n
9=n
Step-by-step explanation:
Answer:
4) wall = 114 ft^2
$118.56 to paint
5) 77 cm^2
Step-by-step explanation:
4) (15 x 8)-(2 x 3)=120-6=114 ft^2
114 x $1.04 = $118.56
5) (14 x 3.5) + (8 x 3.5) = 49 + 28 = 77 cm^2
