7-day average for the positivity rate in Texas
The seven-day average positivity rate is calculated by dividing the number of positive tests by the total PCR lab tests conducted over the last week. A rate over 10% means there is high transmission of the virus in the area, according to the Centers for Disease Control and Prevention. Because this formula relies on the date on which the test was administered, the rates for previous days are recalculated as more test results from those dates come in.