Patient id	sysbp	Drug	at risk
1	159.6	0	1
2	130.5	0	0
3	98.9	0	0
4	137.6	0	0
5	209.7	0	1
6	164.4	0	1
7	125.5	0	0
8	170.8	0	1
9	161.8	0	1
10	216.5	0	1
11	183.5	0	1
12	153.6	0	1
13	145.2	0	1
14	156.6	0	1
15	179.1	0	1
16	181.4	0	1
17	187.7	0	1
18	135.4	0	0
19	154.4	0	1
20	168.5	0	1
21	175.4	0	1
22	151.9	0	1
23	143.1	0	1
24	167.9	0	1
25	165.3	0	1
26	151.8	0	1
27	147.2	0	1
28	132.6	0	0
29	172.3	0	1
1	160.6	1	1
2	182.7	1	1
3	168.5	1	1
4	154.3	1	1
5	112.2	1	0
6	121.1	1	0
7	112.4	1	0
8	149.7	1	1
9	144.2	1	1
10	150.3	1	1
11	176.5	1	1
12	142.5	1	1
13	148.5	1	1
14	148.3	1	1
15	170.2	1	1
16	165.5	1	1
17	160	1	1
18	135	1	0
19	116.1	1	0
20	141.4	1	1
21	135.4	1	0
22	136.7	1	0
23	157.9	1	1
24	119.7	1	0
25	124.9	1	0
26	133.5	1	0
27	173.1	1	1
28	156.1	1	1
29	160	1	1

We have examined whether or not the mean systolic blood pressure differs between the two groups. However, a more important question is whether or not the people who take the drug have a lower proportion at risk because of their blood pressure.

1. Use the chi-square test to test whether the proportion of people at risk due to their blood pressure is different for the people who take the drug compared to the people who do not take the drug. Be sure to fully report the hypothesis test and show why this test can be used with this data set. Report all numbers to 2 decimal places except for degrees of freedom which are reported as whole numbers. Have we proved (choose one)
   1. The null hypothesis is true
   2. The alternative hypothesis is true
   3. Neither a. nor b. (7 marks)