Answer:
<h3>20</h3>
Step-by-step explanation:
Standard deviation of the mean is expressed as:
SM = s/√n
s is the standard deviation of all invoices
n is the sample size of the invoiced
Given
s = $200
n = 100
Required
Standard deviation of the mean
Substitute the given parameters into the given equation
SM = 200/√100
SM = 200/10
SM = 20
Hence the standard deviation of xbar is 20
(2x+1)+(3x-5)=5x-4 you just have to try some of them out and see which ones work
The percentage of the radioactive isotope left is 25.0000%.
<h3>What is the half life?</h3>
The half life of a radioactive isotope is the time that will elapse before only half of the number of original isotopes will remain.
Now;
We are told that;
Half life (t1/2) = 55 days
Time taken (t) = 115 days
Ratio of isotope remaining = N/No
Thus;
N/No = (1/2)^t/t1/2
N/No = (1/2)^115/55
N/No = (1/2)^2
N/No =1/4
Hence, the percentage = 1/4 * 100/1 = 25.0000%
Learn more about half life of an isotope:brainly.com/question/16387602
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Answer:
i just want point lol
Step-by-step explanation: