Question

Calcium blockers are among several classes of medicines commonly prescribed to relieve high blood pressure. A study in Denmark has found that calcium blockers may also be effective in reducing the risk of heart attacks. A total of 897 randomly selected Danish patients, each recovering from a heart attack, were given a daily dose of the drug Verapamil, a calcium blocker. After eighteen months of follow-up, 146 of these patients had recurring heart attacks. In a control group of 878 randomly selected individuals, each of whom took placebos, 180 had a heart attack. At a 1% level of significance, do the data provide sufficient evidence to infer that calcium blockers are effective in reducing the risk of heartattacks? Assume that the samples are independent.

Answer 1

i am indicating calcium blocker as group 1 and placebos as group 2.

hypothesis:-

where, is the population proportion of patients recurring heart attacks after treated with calcium blocker.

where, is the population proportion of patients recurring heart attacks after treated with placebo.

given data and necessary calculation are:-

number of patients recurring heart attack after given a daily dose of the drug Verapamil, a calcium blocker() = 146

number of patients recurring heart attack who had taken placebo() = 180

pooled estimate be:-

the test statistic be:-

z critical value for 99% confidence level one tailed test be:-

[ for left tailed test ]

rejection region:-

reject the null hypothesis if,

z calculated < -2.33

decision:-

so, we fail to reject the null hypothesis.

conclusion:-

there is not sufficient evidence to support the claim that calcium blockers are effective in reducing the risk of heart attacks at 0.01 level of significance.