A physical fitness association is including the mile run in Its secondary - school fitness test. The time for this event for boys in secondary school is known to possess a normal distribution with a mean of 450 seconds and a standard deviation of 60 seconds. Find the probability that a randomly selected boy in secondary school can run the mile in less than 312 seconds. .9893 .5107 O . 0107 .4893 QUESTION 2 5 points Sa A random sample of 40 part-time workers has a mean annual earnings of $3120 and a population standard deviation of $677. Compute the 95% confidence interval for H. ($210, $110) ($1987, $2346 ($4812, $5342) ($2910, $3330 ) QUESTION 3 Construct a 99% confidence interval for the population mean, H . Assume the population has a normal distribution. A group of 19 randomly selected employees has a mean age of 22.4 years with a standard deviation of 3.8 years. O (17.2. 23.6) (18.1, 24.1 ( 16 . 3 , 26.9 ) Find the area of the shaded region. The graph depicts the standard normal distribution with mean 0 and standard deviation 1. -1.84 -0.92 0.8212 0 1788 0 0 3576 0.6424QUESTION S Find the indicated z score. The graph depicts the standard normal distribution with mean 0 and standard deviation 1. Shaded area is 0.0694. O 1.48 O 1.26 O 1.39 O 1.45