Answer:
It'll take approximately 9.1 minutes
Step-by-step explanation:
The decay of this element can be modeled by the following expression:
m(t) = 540*(1 - 0.179)^t
Where m is the mass of the element in a given minute t. This expression comes from a compounded interest formula, with negative rate, since they will work in the same manner. Therefore to find how long until it reaches 90 g, we need to make m = 90 and solve for t.
90 = 540*(0.821)^t
(0.821)^t = 90 / 540
(0.821)^t = 1/6
ln(0.821^t) = ln(1/6)
t*ln(0.821) = ln(1) - ln(6)
t*ln(0.821) = - ln(6)
t = -ln(6)/ln(0.821) = 9.08452
It'll take approximately 9.1 minutes
Answer:
28
Step-by-step explanation:
7 x 4 = 28
hopefully this helps you :)
pls mark brainlest ;)
Step-by-step explanation:
Margin of error = critical value × standard deviation
We aren't given the critical value or any information to calculate it, so we need to make some assumptions. Assuming the data set is large enough to be approximated as normal, and that the confidence level is 95%, then the critical value is 1.96.
ME = 1.96 × 9.5
ME = 18.62
You may choose to round 1.96 to 2, in which case the margin of error is:
ME = 2 × 9.5
ME = 19
Answer:
7.5 cm: 30 cm
Step-by-step explanation:
The scale is 1 cm: 4cm which is 1/4. The next one would be 7.5 cm: 30 cm because that is also equal to 1/4.
The table is:
Number of washes denoted by x: 0, 8, 12
Amount left on card denoted by y: 30, 18, 12
a. Write an equation that shows the amount of dollars left on the card
Solution:
18 – 30 divided by 8 – 0 = -12/8
On simplest form is -3/2
The equation is y = -3/2x + 30
b. Explain the meaning of the negative slope above.
As the number of car washes increase, the dollars left on the card decreases.
c. What is the maximum value of x?
0 = -3/2x + 30
2/3 x 3/2 x = 30/1 x 2/3
Cancel 2/3 x 3/2 and reduce 30 by 3 we get 10, 10 x 2
x = 20
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