5 (10) A medical researcher wishes to evaluate the effectiveness of a drug in prolonging the life of a red cell in a culture medium. Seven cultures are treated with saline (an inactive control substance) and seven others are treated with the new drug. The following survival times in days were recorded:

Control GroupTreatment Group

109 121

112 119.

118 119

116 126

121 121

100 115

113 117

a. State the null hypothesis.

b. State the nondirectional alternative hypothesis.

c. What is the value of t₀bt?=

SS control = SS treat =

T =(112.7143-119.7143)/SQRT (283.43+73.43)/12(.2857)=

7/2.9148 = -

e. What do you conclude using = 0.05 2 tail?

f. What is the size of the effect using omega squared?

• ² = t_obt² -1
• t_obt² +N-1

g. What is the size of the effect using cohen's d?

• Estimated d = Xbar1-Xbar2
• SQRT(pooled variance)

Cohen d =