1 5 points Save Answer How long does it take juniors to complete a standardized exam? The long-term average is 2.8 hours. We may assume that X has a normal distribution with 0= 0.8 hour. A random sample of 12 juniors had a sample mean 'x-bar' of = 2.2 hours. Does this indicate that the population mean time is different from 2.8 hours? Use 5% level of signicance. (a) State the null and alternate hypotheses and the level of significance. Is the test left-tailed, right-tailed, or two-tailed? (b) Identify the appropriate sampling distribution: the standard normal or the Student's t. What is the value of the sample test statistic? (c) Find (or estimate) the P-value. Sketch the sampling distribution and show the area