The given sequence is not in numerical order. The numbers are not increasing or decreasing consistently. However, if we observe closely, we can see that the numbers are alternating between increasing and decreasing. The first number is 48, then it increases to 59, then decreases to 50, then increases to 69, and finally increases again to 79. Therefore, the missing number in the sequence should be the next number in the alternating pattern, which is 50.