K Assume that females have pulse rates that are normally distributed with a mean of 75 0 beats per minute and a standard deviation of a 12 5 beats per minute Complete parts a throu below a If 1 adult female is randomly selected find the probability that her pulse rate is less than 78 beats per minute The probability is Round to four decimal places as needed b If 4 adult females are randomly selected find the probability that they have pulse rates with a mean less than 78 beats per minute The probability is Round to four decimal places as needed c Why can the normal distribution be used in part b even though the sample size does not exceed 30 O A Since the distribution is of sample means not individuals the distribution is a normal distribution for any sample size OB Since the distribution is of individuals not sample means the distribution is a normal distribution for any sample size OC Since the mean pulse rate exceeds 30 the distribution of sample means is a normal distribution for any sample size O D Since the original population has a normal distribution the distribution of sample means is a normal distribution for any sample size