Given: To test a car's exhaust fumes, an inspector took six samples. The exhaust samples contained the following amounts of gas in parts per million (ppm); 8,5,7,6,9 and 5. The maximum allowable mean is 6 ppm.
Required: To identify whether the vehicle passed the test.
Explanation: The mean of the data is given by the formula,
[tex]\text{ Mean=}\frac{\text{ Sum of all observations}}{\text{ Total number of observations}}[/tex][tex]\text{ Mean=}\frac{\text{8+5+7+6+9+5}}{6}[/tex][tex]\begin{gathered} \text{ Mean=}\frac{40}{6} \\ \text{ Mean=6.67 ppm} \end{gathered}[/tex]Since the maximum allowable mean was 6 ppm and the mean of the sample is 6.67, which is greater than the allowed mean. Therefore the car failed the test.
Final Answer: The car did not pass the test.
