Answer:
50%
Step-by-step explanation:
Answer: 693 years
Step-by-step explanation:
Expression for rate law for first order kinetics is given by:

k = rate constant
t = time taken for decomposition = 1
= Initial amount of the reactant
= amount of the reactant left =



for half life : 

Putting in the values , we get


Thus half life of this isotope, to the nearest year is 693.
Answer:
Step-by-step explanation:
76
I think that the 4 sisters get 3 pieces each of the muffins because if you cut it in four pieces it gives one piece to each one of the four sisters and you keep doing it with the other two left muffins.
Answer:
The critical value is T = 1.895.
The 90% confidence interval for the mean repair cost for the washers is between $48.159 and $72.761
Step-by-step explanation:
We have the standard deviation for the sample, so we use the t-distribution.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 8 - 1 = 6
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 6 degrees of freedom(y-axis) and a confidence level of
. So we have T = 1.895, which is the critical value.
The margin of error is:

In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 60.46 - 12.301 = $48.159
The upper end of the interval is the sample mean added to M. So it is 60.46 + 12.301 = $72.761
The 90% confidence interval for the mean repair cost for the washers is between $48.159 and $72.761