Answer:
For a sample size of 10, the t-value is about 3.25 (from tables) at a 99% confidence interval.
Explanation:
When the standard deviation for the population is not known, the confidence interval estimate for the population mean is performed with the Student's t-distribution.
The confidence interval for the mean is calculated as

where

= sample mean,
s = sample standard deviation,
t = t-value (provided in tables),
n = sample size.
When reading the t-value, (n-1) is called the df or degrees of freedom.
Answer:
x = -11/5 and y = 24/5
Step-by-step explanation:
Use elimination.
First, we need to multiply so that at least one variable can cancel out.
We can multiply the top equation by 2.
So we get
4x + 6y = 20
Then, we can use elimination.
The x's cancel out.
So we get 5y = 24
Or y = 24/5
Then, we can plug in this y value back into the first equation to find x.
2x + 3(24/5) = 10
2x + 72/5 = 50/5
2x = -22/5
x = -11/5
So x = -11/5 and y = 24/5
It would be 2,0 for the x and y