Solution :
Two sample T-test and CI : Conventional methods, New methods
Two sample T for conventional method Vs new method
N Mean StDev Se Mean
Conventional mean 30 35.3 20.8 3.8
New methods 30 35.1 22.3 4.1
Difference = μ (conventional method) - μ (new method)
Estimate for difference : 0.17
95% CI for difference : (-10.976, 11.309)
T-Test of difference = 0(vs <): T-value = 0.03 P-value =0.5119 DF = 57
95% confident that the true mean difference in mean crying time after being given a vitamin K shot between infants using conventional methods and infants held by their mothers is between -10.976 and 11.309. In other words, the mean crying time of infants given vitamin K shot using conventional methods is anywhere from -10.976 less than to 11.309 more than the mean crying time of infants given vitamin K shot using new methods.