Question

The objectives of a study by Skjelbo et al. were to examine (a) the relationship between Chloroguanide metabolism and efficacy in malaria prophylaxis and (b) the mephenytoin metabolism and its relationship to chloroguanide metabolism among Tanzanians. From information provided by urine specimens from the 216 subjects, the investigators computed the ratio of unchanged S-mephenytoin to R-mephenytoin (S/R ratio). The results were as follows:

0.0269 0.0400 0.0550 0.0550 0.0650 0.0670 0.0700 0.0720 0.0760 0.0850 0.0870 0.0870 0.0880 0.0900 0.0900 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.0990 0.1000 0.1020 0.1040 0.1050 0.1050 0.1080 0.1080 0.1090 0.1090 0.1090 0.1160 0.1190 0.1200 0.1230 0.1240 0.1340 0.1340 0.1370 0.1390 0.1460 0.1480 0.1490 0.1490 0.1500 0.1500 0.1500 0.1540 0.1550 0.1570 0.1600 0.1650 0.1650 0.1670 0.1670 0.1677 0.1690 0.1710 0.1720 0.1740 0.1780 0.1780 0.1790 0.1790 0.1810 0.1880 0.1890 0.1890 0.1920 0.1950 0.1970 0.2010 0.2070 0.2100 0.2100 0.2140 0.2150 0.2160 0.2260 0.2290 0.2390 0.2400 0.2420 0.2430 0.2450 0.2450 0.2460 0.2460 0.2470 0.2540 0.2570 0.2600 0.2620 0.2650 0.2650 0.2680 0.2710 0.2800 0.2800 0.2870 0.2880 0.2940 0.2970 0.2980 0.2990 0.3000 0.3070 0.3100 0.3110 0.3140 0.3190 0.3210 0.3400 0.3440 0.3480 0.3490 0.3520 0.3530 0.3570 0.3630 0.3630 0.3660 0.3830 0.3900 0.3960 0.3990 0.4080 0.4080 0.4090 0.4090 0.4100 0.4160 0.4210 0.4260 0.4290 0.4290 0.4300 0.4360 0.4370 0.4390 0.4410 0.4410 0.4430 0.4540 0.4680 0.4810 0.4870 0.4910 0.4980 0.5030 0.5060 0.5220 0.5340 0.5340 0.5460 0.5480 0.5480 0.5490 0.5550 0.5920 0.5930 0.6010 0.6240 0.6280 0.6380 0.6600 0.6720 0.6820

  

(b) The investigators defined as poor metabolizers of mephenytoin any subject with an S/R mephenytoin ratio greater than .9. How many and what percentage of the subjects were poor metabolizers?

(c) How many and what percentage of the subjects had ratios less than .7? Between .3 and .6999 inclusive?

Answer 1

b) By observing the data, no any observation is greater than 0.9 S/R ratio. Hence 0% of subjects were poor metabolizers.

c) All are observaion has ratio less than 0.7 and hence 100% of subjects had ratio less than 0.7.

56 observations are lies in between 0.3 and 0.6999 and hence 29.17% of subjects had these ratio.

I have attached the image in which all calculations are carried out. Frequency of each observation is obtain using pivot table such as on row all the unique observations and on column count of each unique observation.