Eastwood's BA201 Assignments

26.        H_o:  m ³ 10                    H₁: m <10         

Reject H_o if z < -1.65                               

Reject H_o.  The mean weight loss is less than 10 pounds.  p-value = P(Z<-2.53) = 0.0057

28.        H_o:  m = $30,000                        H₁: m ¹ $30,000

            Reject H_o if z < -1.65 or z > 1.65                       

            Reject H_o.  We can conclude that the mean salary is not $30,000.  p-value is 0.0672, found by 2(0.0336)

30.        H_o:  m £ 1.25                 H₁: m >1.25                   Reject H_o if z > 1.65     

            Reject H_o.  The mean price of gasoline is greater than $1.25.  The p-value = P(Z>2.37) = 0.0089

34.        H_o:  m₁ ³ m₂                   H₁: m₁ < m₂                      Reject H_o if z < -1.65

            Fail to reject H_o.  There is not enough evidence to conclude that more units are produced on the afternoon shift. Note that the p-value = P(Z< -1.30) =.0968

36.        H_o:  m₁ ³ m₂                   H₁: m₁ < m₂                          Reject H_o if z < -2.33

            H_o is rejected.  The mean number of cups for regular coffee drinkers is less.
 p-value = P(Z<-5.4) = 3.340 x 10^-8 = 0.0000000334 » 0

38.        H_o:  m₁ £ m₂                   H₁: m₁ > m₂                          Reject H_o if z > 2.33

            Reject H_o and conclude that the fog index is higher in scientific journals. Note that the p-value = P(Z<-4.1) = 2.067 x 10^-5 = 0.00002067 » 0

40.        H_o:  p £ 0.55                 H₁: p >0.55                   H_o is rejected if z > 1.65

            H_o is not rejected.  We cannot conclude that more than 55% of the commuters would use the route. Note that the p-value = P(Z>0.84) = P(Z<-0.84) = .2005

42.        H_o:  p £ 0.10                 H₁: p >0.10                   H_o is rejected if z > 1.65

            H_o is rejected.  More than 10 percent of the sets need repair.  p-value = P(Z<-1.89) = 0.0294

44.        H_o:  p₁ £ p₂      H₁: p₁ > p₂       Reject H_o if z > 1.65

            H_o is not rejected.  There is not enough evidence to establish a difference in the proportions that found relief from the new and the old drugs. Note the p-value = P(Z<-1.02) = .1539

46.        H_o:  p_m = p_w     H₁: p_m ¹ p_w      Reject H_o if z < -1.96 or z > 1.96

            H_o is not rejected.  There is not evidence to establish a difference in the proportion of men and women who are pack-a-day smokers. The p-value was not requested, but it equals 2P(Z<-1.64) = 2(.0505) = .1010

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