Damage to homes caused by burst piping can be expensive to repair. By the time the leak is discovered, hundreds of gallons of water may have already flooded the home. Automatic shutoff valves can prevent extensive water damage from plumbing failures. The valves contain sensors that cut off water flow in the event of a leak, thereby preventing flooding. One important characteristic is the time (in milliseconds) required for the sensor to detect the water flow. The data obtained for four different shutoff valves are contained in the file titled Waterflow. The differences between the observed time for the sensor to detect the water flow and the predicted time (termed residuals) are listed and are assumed to be normally distributed. Using the four sets of residuals given in the data file, determine if the residuals have a normal distribution. Use a chi-square goodness-of-fit test and a significance level of 0.05. Use five groups of equal width to conduct the test.