Answer:
1st Question
A. 85
2nd Question
B. 71
Step-by-step explanation:
1st Question
{90 + 94 + 96 + 90} = 370/4 = 92.5
{95 + 99} = 194/2 = 97
{87 + 75 + 82 + 85} = 329/4 = 82.25
{71} = 71/1 = 71
.20(92.5) +.25(97) +.30(82.25) +.25(71) = 85.175 Rounded-up = 85
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2nd Question
.10(95) +.20(80) +.50(67) +.20(60) = 71
3000x1.12
=3360
Therefore, Frankie will have £3360 percent chance for at the end if the time period
Answer:
the question is incomplete, so I looked for a similar one:
<em>After the release of radioactive material into the atmosphere from a nuclear power plant, the hay was contaminated by iodine 131 ( half-life, 8 days). If it is all right to feed the hay to cows when 10% of the iodine 131 remains, how long did the farmers need to wait to use this hay? </em>
iodine's half life (we are given x, we need to find b):
0.5A₀ = A₀eᵇˣ
x = 8 days
we eliminate A₀ from both sides
0.5 = eᵇ⁸
ln 0.5 = ln eᵇ⁸
-0.69315 = b8
b = -0.69315 / 8 = -0.08664
since the farmers need to wait until only 10% of the iodine remains (we already calculated b, now we need to find x):
0.1A₀ = A₀eᵇˣ
0.1 = eᵇˣ
ln 0.1 = bx
where b = -0.08664
x = ln 0.1 / -0.08664 = -2.302585 / -0.08664 = 26.58 days
