Answer: -29.3
Step-by-step explanation: -7y + 2x
-7(-6.3) + 2(-7.4) = -29.3
Answer:
For this case the confidence interval is given by :

Step-by-step explanation:
Data provided
represent the sample mean for the fuel efficiencies
population mean
s=2.51 represent the sample standard deviation
n=601 represent the sample size
Confidence interval
The formula for the confidence interval of the true mean is given by:
(1)
The degrees of freedom for this case is given by:
The Confidence level for this case is 0.95 or 95%, and the significance level
and
and the critical value is given by
Replcing into the formula for the confidence interval is given by:
For this case the confidence interval is given by :

Answer: ![t\in [\dfrac{1}{4},2]](https://tex.z-dn.net/?f=t%5Cin%20%5B%5Cdfrac%7B1%7D%7B4%7D%2C2%5D)
Step-by-step explanation:
Given
Inequality is 
Taking variables one side

Using wavy curve method
![t\in [\dfrac{1}{4},2]](https://tex.z-dn.net/?f=t%5Cin%20%5B%5Cdfrac%7B1%7D%7B4%7D%2C2%5D)