The United States earned 104 medals at the 2012 summer olympics. The number of silver medals earned was the same as the number o
1 answer:
You might be interested in
Answer:
And the best option would be:
D. (0.191 to 0.249)
Step-by-step explanation:
For this case we know that the mean is:
And the standard error is given by:
We want to construct a 68% confidence interval so then the significance level would be :
and
. The confidence interval is given by:
Now we can find the critical value using the normal standard distribution and we got looking for a quantile who accumulate 0.16 of the area on each tail and we got:
And replacing we got:
And the best option would be:
D. (0.191 to 0.249)
The question is incomplete, here is the complete question:
The half-life of a certain radioactive substance is 46 days. There are 12.6 g present initially.
When will there be less than 1 g remaining?
<u>Answer:</u> The time required for a radioactive substance to remain less than 1 gram is 168.27 days.
<u>Step-by-step explanation:</u>
All radioactive decay processes follow first order reaction.
To calculate the rate constant by given half life of the reaction, we use the equation:
where,
= half life period of the reaction = 46 days
k = rate constant = ?
Putting values in above equation, we get:
The formula used to calculate the time period for a first order reaction follows:
where,
k = rate constant =
t = time period = ? days
a = initial concentration of the reactant = 12.6 g
a - x = concentration of reactant left after time 't' = 1 g
Putting values in above equation, we get:
Hence, the time required for a radioactive substance to remain less than 1 gram is 168.27 days.