Quiz: S... Question 3 3 pts Suppose at University of Toronto, the population of students spend an average of 9 hours per week for physical exercises at gym with a standard deviation of 4 hours. Based on a sample of 64 students, what is the standard error of the sample mean? O 4 hours 1.125 hours O 0.444 hours O 0.5 hours Question 4 3 pts What are the critical values of t, for a two tailed test for testing one population mean, with a=10%, and sample size of 15? O -1.345 and 1.345 O -2.977 and 2.977 O -1.761 and 1.761 O -2.624 and 2.624 SC 20 F1 F2 F3 F4 F5 a % 2 4 5Question 5 3 pts According to Chebyshev's theorem, at least what percent of the observations lie within plus and minus 2.25 standard deviations of the mean? 75% 0 64% 0 95% 80% Question 6 3 pts Suppose independent random samples that are taken to test the difference between the means of two populations. The variances of the populations are unknown but are assumed to be unequal. The sample sizes are n1 = 35 and n2 = 44. The sample standard deviations are s1 = 75 and s2 = 58. The appropriate distribution to use is the: O t distribution with df = 77 O t distribution with df = 63 O t distribution with df = 62 O F distribution with numerator df = 34 and denominator df = 43 C O O- F1 20 F2 F3 F4 F5 a LA % 2 5Question 9 3 p Suppose you are designing a sample to find the mean age for young adults who commit crimes, with a maximum error of one year, with 99% of confidence level. If we know that population standard deviation is 6 years, the smallest sample size that you need is almost: 138 239 O 97 324 Question 10 3 pts Suppose on average there are 5 plane crashes per year. Using Poisson probability distribution, the probability that there will be only 2 plane crashes next year is almost: 40.0% O 3.6% 8.4% 14.9% esc F1 20 F2 F3 F4 F5 a $ 2 Co 5