Question

Researchers conducted a study to investigate the effectiveness of two different treatments for depression (Lithium or Imipramine). A sample of individuals diagnosed with bipolar depression were divided into three groups - one group received Lithium, one group received Imipramine, and the last group was given a placebo. After a specified length of time, patients are evaluated for a recurrence of depression. Use StatCrunch to conduct a chi-square test to determine if recurrence is related to the treatment prescribed. In StatCrunch, select Stat > Tables > Contingency > With Data. Select one of the variables of interest for the row variable and the second variable as the column variable. Then click Compute.

• Select the appropriate hypotheses:
  • HoHo: recurrence of depression is related to the treatment prescribed
    HaHa: recurrence of depression is not related to the treatment prescribed
  • HoHo: recurrence of depression is not related to the treatment prescribed
    HaHa: recurrence of depression is related to the treatment prescribed
• TS: χ2χ2 =   (round to 4 decimal places)
• probability =    (round to 4 decimal places)
• Conclusion: At the 0.10 level, there Select an answer is is not  significant evidence to conclude recurrence of depression Select an answer is not is  related to the treatment prescribed.

Throwback Question: Suppose we know that the risk of liver cancer among alcoholics without cirrhosis of the liver is 29.8%. A researcher conjectures that the risk of cancer among alcoholics with cirrhosis of the liver is higher. Suppose we sample 81 alcoholics with cirrhosis of the liver and determine 29 have liver cancer. Use this information to answer the following:

1. For each person in the sample, what variable is recorded?
   • number of years diagnosed with cirrhosis
   • level of alcoholism
   • percentage of individuals with liver cancer
   • if the individual has liver cancer
2. Completely describe the sampling distribution for the sample proportion of alcoholics with cirrhosis who have liver cancer when samples of size 81 are selected (assuming there is no difference in occurrence between those with and without cirrhosis).
   • mean: μˆpμp^  =
   • standard deviation: σˆpσp^ =  (round to 4 decimal places)
   • shape: the distribution of the sample proportion is Select an answer not normally distributed normally distributed   
     • Checks: np =  and n(1 - p) =
3. Test the appropriate claim using the data collected at a significance level of 0.10.
   • HoHo : p ? < > = ≠     HaHa : p ? = < > ≠  
   • αα =
   • TS: z =   (round your final answer to 2 decimal places; carry 4 decimal places throughout your calculation)
   • probability =   (round to four decimal places)
   • Decision: Select an answer fail to reject H₀ reject H₀
   • Interpretation:At the 0.10 level, there Select an answer is is not   significant evidence to support the claim that the incidence rate of liver cancer is Select an answer lower higher different than   in alcoholics diagnosed with cirrhosis.

Answer 1