Answer:
The lower quartile corresponds to the 25th percentile of the data set. To find the maximum value for the lower quartile, we need to find the largest number that is at or below the 25th percentile.
The range of the numbers that the random number generator can pick is 69 - 7 + 1 = 63. The 25th percentile corresponds to the value that is 25% of the way through this range, which is:
0.25 * 63 = 15.75
Since we can't pick a fractional number, we need to round down to 15. Therefore, the maximum value for the lower quartile is 15.