7. 8.53 An engineer was asked to determine whether the average air quality index (AQI) in a volatile chemical mixing room was within OSHA guidelines. The following nine AQI readings in ppm (parts per million) were collected: 181, 186, 180, 191, 183, 183, 196, 185, and 189 1. Determine the arithmetic mean. 2. Calculate the standard deviation. 3. Determine the percent of readings that fall within ±1 standard deviation from the mean. 4. Verify your answers using spreadsheet functions. 5. The AQI categories and health concerns are shown below. Based on the value of the upper limit of the range you determined in part (c), what can you conclude about the air quality condition in the mixing room? Table Summary: Table divided into two columns shows state of air quality based on the quantity of pollutants. The column headers are marked from left to right as: air quality index (AQI) values and levels of health concern. The column subheaders are marked from left to right as: when the AQI is in this range and air quality conditions are. Air Quality Index (AQI) Values Levels of Health Concern When the AQI is in this range: ..air quality conditions are: 0 to 50 Good 51 to 100 Moderate 101 to 150 Unhealthy for Sensitive Groups 151 to 200 Unhealthy Air Quality Index (AQI) Values Levels of Health Concern When the AQI is in this range: ..air quality conditions are: 201 to 300 Very Unhealthy 301 to 500 Hazardous