The following table lists the results from a trial testing the effectiveness of

Question

The following table lists the results from a trial testing the effectiveness of Warfarin in preventing vascular deaths.

Number Vascular Deaths Total in Group p

Warfarin 82 607

Placebo 105 607

Pc

15)(4 pts) Calculate the estimated proportions p , and construct two 95% Confidence intervals to estimate the intervals for the proportion in each of the 2 groups (Warfarin and Placebo) that suffer vascular death.

16) (3pts) At what significance level does this data give evidence that the proportion of people in the Placebo group who suffer vascular death is Higher than or Greater than the proportion of patients in the Warfarin group who suffer vascular deaths.

Explanation / Answer

The following table lists the results from a trial testing the effectiveness of Warfarin in preventing vascular deaths.

Number Vascular Deaths Total in Group p

Warfarin 82 607

Placebo 105 607

Calculate the estimated proportions p , and construct two 95% Confidence intervals to estimate the intervals for the proportion in each of the 2 groups (Warfarin and Placebo) that suffer vascular death.

Proportion we can find by using formula :

p^ (warfarin) = Number Vascular Deaths due to warfarin) / total in group

p^ (warfarin) =  82/607 = 0.14

p^(placebo) = 105/607 = 0.17

At what significance level does this data give evidence that the proportion of people in the Placebo group who suffer vascular death is Higher than or Greater than the proportion of patients in the Warfarin group who suffer vascular deaths.

Here we have to test the hypothesis that,

H0 : p1 = p2 Vs H1 : p1 > p2

where p1 is the proportion of people in the Placebo group who suffer vascular death.

p2 is the proportion of people in the warfarin group who suffer vascular death.

Assume alpha = level of significance = 0.05

Here test statistic follows normal distribution.

Now we can test this hypothesis using TI-83 calculator.

steps :

STAT --> TESTS --> 6:2-PropZTest --> ENTER --> Input all the values --> select alternative ">P2" --> ENTER --> Calculate --> ENTER

Output :

Test statistic (Z) = 1.83

P-value = 0.034

P-value < alpha

Reject H0 at 5% level of significance.

COnclusion : There is sufficient evidence to say that proportion of people in the Placebo group who suffer vascular death is Higher than or Greater than the proportion of patients in the Warfarin group who suffer vascular deaths.

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.