A mechanical engineering team at an automotive company has developed a new coolant additive designed to reduce engine operating temperature. To test its effectiveness, the team installs temperature sensors in 10 test vehicles. They first measure the peak steady-state engine temperature of each vehicle using a standard coolant mixture. Then, they drain the system, add the new additive to the coolant, and repeat the exact same test on the same 10 vehicles under identical conditions.
The peak temperature data (in degrees Celsius) for each vehicle, before and after the additive, is recorded below.
| Vehicle ID | Temperature Before Additive (°C) | Temperature After Additive (°C) |
| 1 | 95.8 | 93.2 |
| 2 | 99.1 | 97.0 |
| 3 | 94.5 | 93.1 |
| 4 | 101.2 | 99.5 |
| 5 | 98.6 | 96.3 |
| 6 | 97.3 | 95.9 |
| 7 | 102.0 | 100.1 |
| 8 | 96.2 | 94.8 |
| 9 | 98.8 | 96.2 |
| 10 | 100.5 | 98.9 |
You are asked to determine if there is statistically significant evidence that the new additive reduces engine temperature. Us significance level of 95%.