Soledad and Tania are both high school students. The number of texts Soledad sends daily, s, is approximately normally distributed with a mean of 100 and a standard deviation of 6 texts. The number of texts Tania sends daily, t, is approximately normally distributed with a mean of 108 and a standard deviation of 8.1 texts. Assume that s and t are independent random variables. Let =−d=s−t. What is the probability that Soledad sends more texts on a randomly selected day?
a) 0.104
b) 0.214
c) 0.786
d) 0.896