Answer:
5
Step-by-step explanation:
y intercept: when x = 0
5(0) + 3y = 15
3y = 15, y = 5
The y intercept is 5
You can put them vertically
then subtract them
but if you do it, it will be 0=-10 that doesn't make sense.
So the answer is that there is no answer!
Whats the original question you got from your teacher
Radioactive half-life is the time it takes for half an amount of radioactive material to decay into something else. In this case, it is assumed that the decay product is not radioactive or otherwise hazardous.
We must use the radioactive decay formula to determine at what time the radiation reaches a safe level.
A = Ao[e^(-0.693)(t)(t 1/2) where t 1/2 is the half-life, t is elapsed time, Ao is the original quantity, A is the future quantity.
We are given a half-life of 2.4 days , an Ao of 1.25 and an A of 1.00:
1.00 = (1.25)e^(-0.693)(2.4)t
1.00/1.25 = e^(-1.6632)t
0.8 = e^(-1.6632)t
t = 0.135 days = 3 hrs 15 min
This is the amount of time to a "safe level" using only radioactive decay, not venting or other means.
Answer:
Step-by-step explanation:
If we assume that the number of arrivals is normally distributed and we don't know the population standard deviation, we can calculated a 95% confidence interval to estimate the mean value as:
where x' is the population mean value, x is the sample mean value, s is the sample standard deviation, n is the size of the sample, 
is equal to 0.05 (it is calculated as: 1 - 0.95) and 
is the t value with n-1 degrees of freedom that let a probability of 
on the right tail.
So, replacing the mean of the sample by 49, the standard deviation of the sample by 17.38, n by 10 and by 2.2621 we get:
Finally, the interval values that she get is:
