Answer:
Step-by-step explanation:
<u>Confidence Interval</u>
When the population standard deviation 
is known, the formula for a confidence interval for a population mean 
is:
Where n is the sample size and z is the corresponding z-value from the standard normal distribution for the selected confidence level. The value of z for a 95% confidence interval is z=1.96. The rest of the values are
Calculating the confidence interval
Or, equivalently
Answer:
23x = -115
Step-by-step explanation:
In the substitution method, you must solve for 1 variable in 1 equation to replace it in the other equation. For the system:
2x - 7y = 4
3x + y = -17
Solving for y in the second equation:
y = -17 - 3x
Replacing y in the first equation:
2x - 7(-17 - 3x) = 4
2x + 119 + 21x = 4
23x = -115
This is the new equation after use the substitution method.
To find out if the triangle is a right triangle, we must check if the following equation is true:
on the left side, we have:
and on the right side, we have:
since on both sides we get 625, we have that the brace forms a right triangle.
Answer:
Electricity is the flow of electrical power or charge. It is a secondary energy source which means that we get it from the conversion of other sources of energy, like coal, natural gas, oil, nuclear power and other natural sources, which are called primary
