A statistics student recorded the number of hours she slept each night for a week. The number of hours are as follows: 7, 8, 7, 9, 6, 7, 8. What is the lower or first quartile of this data set?

Step 1 ：Step 1: First, we need to arrange the data in ascending order. The ordered data set is: \(6, 7, 7, 7, 8, 8, 9\)

Step 2 ：Step 2: The lower quartile, or first quartile, is the median of the first half of the data set. Since there are 7 data points, the first half of the data set includes the first 3 numbers. So, we find the median of these three numbers. The median is the middle number, or the second number in this case, which is 7.