Answer: 23+32-3×4-52÷5+(7×4)= 60.6
Step-by-step explanation:
Answer:
And we are 95% confident that the true mean of chloride concentration is between 0.375 and 0.377 cc/ cubic meter
Step-by-step explanation:
Data provided
represent the sample mean for the chloride concentration
population mean (variable of interest)
s=0.0012 represent the sample standard deviation
n=15 represent the sample size
Confidence interval
The confidence interval for the mean is given by the following formula:
(1)
Since we need to find the critical value first we need to begin finding the degreed of freedom
The Confidence is 0.95 or 95%, the significance would be
and
, and the critical value for this case with a t distribution with 14 degrees of freedom is
And the confidence interval is:
And we are 95% confident that the true mean of chloride concentration is between 0.375 and 0.377 cc/ cubic meter
Answer:
(-3, -2)
Step-by-step explanation:
Look at the second equation, we can easily rearrange it to make x the subject.
x - 4y = 5
x = 4y + 5
Now lets put that into the second equation
2x - 2y = -2
2(4y + 5) - 2y = -2
6y + 10 = -2
6y = -12
y = -2
Now lets find x!
x = 4y + 5
x = 4(-2) + 5
x = -3
Now lets format the answer like the question says (ordered pair)
(-3, -2)
Recap: We used substitution and made an equation to work out one of the variables first, then found the second variable using the first.
50 is a rational number because it can be expressed in two integers; 50 ÷ 1