Answer:

Step-by-step explanation:
The confidence interval for the population mean x can be calculated as:

Where x' is the sample mean, s is the population standard deviation, n is the sample size and
is the z-score that let a proportion of
on the right tail.
is calculated as: 100%-99%=1%
So, 
Finally, replacing the values of x' by 308, s by 17, n by 15 and
by 2.576, we get that the confidence interval is:

I would say that the results of the study are not significant. This is because the difference of those who drink tea and did not drink tea is small and more or less will have the same values at some points of the research. Having a difference of 0.024, cannot really say anything or differentiate the two.
Answer:
A repeating decimal can be written as a fraction using algebraic methods, so any repeating decimal is a rational number.
Marco is wrong cuz its not repeating
Answer:
x = 2
y = 4
z = 8
1. xy
10
2. x + z
8
3. z - y
4
4. x + y + z
14Step-by-step explanation: