Question

STA2221 examples on CI & Testing of Hypothesis Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answer the question Provide an appropriate response. 1) Find the critical value,te for 0.99 and n-10. A) 3.250 B) 3.169 1.833 D) 2.262 2) Find the critical value to forc=0.95 and n=16. A) 2.947 B) 2.602 2120 D) 2.131 3) Find the value of E, the margin of error, for A) 1.69 B) 0.42 0.99, n=16 and s=2.6. C) 1.92 D) 0.48 4) Find the value of A) 1.80 the margin of error, forc=0.90, n=10 and s-3.1. B) 0.57 C) 1.36 D) 1.78 5) Construct the indicated confidence interval for the population mean y using the t-distribution 5 C=0.95, X 645,5 31, n 16 A) (876.2, 9815) B) (321.7,365.8) (628.5, 661.5) D) (531.2. 6129) 6) In a random sample of 28 families, the average weekly food expense was $95.60 with a standard deviation of $22.50. Determine whether a normal distribution or at-distribution should be used or whether neither of these can be used to construct a confidence interval Assume the distribution of weekly food expenses is normally shaped A) Use normal distribution. B) Cannot use normal distribution or t-distribution C) Use the t-distribution 7) For a sample of 20 IQ scores the mean score is 105 8. The standard deviation, a, is 15. Determine whether a normal distribution or a t-distribution should be used or whether neither of these can be used to construct a confidence interval. Assume that IQ scores are normally distributed A) Use the t-distribution B) Carnot use normal distribution or t-distribution C) Use normal distribution ) 8) A random sample of 15 statistics textbooks has a mean price of $105 with a standard deviation of $30.25. Determine whether a normal distribution or at-distribution should be used or whether neither of these can be used to construct a confidence interval. Assume the distribution of statistics textbook prices is not normally distributed A) Use the t-distribution B) Cannot use normal distribution or t-distribution C) Use normal distribution

Answer 1

#by using t 1) The critical value, te forc=0.gg and n=10 15 - table where gris degrees of freedom and 0.005=2/2 = 0.0 to.oos, by = 3.250 is : correct choice A) 3.250 - 2) The t critical value at 95% confidence Level with 2-1=15 degrees of freedom is - too25, 15 = 2.131 # by using S t table correct choice is D) 2131

3) The margin of n=16 and s= 2.6 Error, is for c= 0.99 given by E = tool 2.6-13* in #by using = +0.005, 16 x 2.1 do trable = 2.94780.65 to.oos, is=2.947 = 1.9155 E = 1.92 conrect choice is c) 192 4) The margin of error for C= 0.go. 010 and :3.1 given by E = tolo, mix it in a toos, gx 3.1 = 1.833x .822 0.9803 1796 = 1.80 :- E -1.80)