A major airline wants to estimate its average number of unoccupied seats per flight over the past year. To accomplish this, the records of 225 flights are randomly selected and the number of unoccupied seats is noted for each of the sampled flights. The results show the sample mean is 11.6 and the sample standard deviation is 4.1. Which one of the following represents a 90% confidence interval for u, the mean number of unoccupied seats per flight during the past year? 11.6 - 2.069(4.1)/15 < µ < 11.6 + 2.069(4.1)/15 11.6 - 1.96(4.1)/15 < µ < 11.6 + 1.96(4.1)/15 11.6 - 1.645(4.1)/15 < µ < 11.6 + 1.645(4.1)/15 11.6 - 2.75(4.1)/15 < µ < 11.6 + 2.75(4.1)/15 11.6 - 1.645(4.1)/225 < H < 11.6 + 1.645(4.1)/225

If there are 5 dishes, they can be relished in any order at a time. In permutation, it should be in a particular order. In combination, the order does not matter. Take 3 letters a, b, and c. The possible ways of pairing any two letters are ab, bc, ac, ba…

The fundamental counting principle is a rule that is used to count the total number of possible outcomes in a given situation.