Answer:
5/6
Step-by-step explanation:
Hope this helped!!!
The amount of the radioactive substance is 374.6 g
<h3>How to determine the amount of
radioactive substance?</h3>
The given parameters are:
- Initial, a = 424 mg
- Rate, r = 6%
- Time, t = 2 hours
The amount of the radioactive substance is calculated as:
A(t) = a(1 - r)^t
This gives
A(t) = 424 * (1 - 6%)^t
At 2 hours, we have:
A(2) = 424 * (1 - 6%)^2
Evaluate
A(2) = 374.6
Hence, the amount of the radioactive substance is 374.6 g
Read more about exponential functions at:
brainly.com/question/2456547
#SPJ1
Both diameter and height are scaled by 2.5.
Area is measured in squared units ( square centimetres).
Square the scale factor:
2.5^2 = 6.25
Multiply the area of the smaller vase by the scale:
2826 x 6.25 = 17,662.5 square cm.
Answer:
The sample mean is
b.3.55
The margin of error is
0.32
Step-by-step explanation:
Deep explanation about a confidence interval
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
So it is z with a pvalue of
, so 
Now, find M as such

In which
is the standard deviation of the population and n is the size of the sample.

The lower end of the interval is the mean subtracted by M. So it is 6.4 - 0.3944 = 6.01 hours.
The upper end of the interval is the mean added to M. So it is 6.4 + 0.3944 = 6.74 hours.
In this problem:
The deep explanation is not that important.
We just have to recognize that the interval has a lower end and an upper end. The distance from both the upper and the lower end to the mean is M. This means that the sample mean is the halfway point between the lower end and the upper end.
The margin of error is the distance of these two points(lower and upper end) to the mean.
In our interval
Lower end: 3.23
Upper end: 3.87
Sample mean

So the correct answer is:
b.3.55
The margin of error is
3.87 - 3.55 = 3.55 - 3.23 = 0.32
Answer:
Her mother will donate $11.20
Step-by-step explanation:
- $0.40 every 0.75 miles.
- 21 miles biked.
Step 1: Figure out how many 0.75 increments are in 21 miles.
21 ÷ 0.75 = 28
- There are 28 increments of 0.75 in 21 miles.
Step 2: Multiply 28 by $0.40
28 * $0.40 = $11.20