Question

1. Errors in medical prescriptions occur relatively frequently. In a study, two groups of doctors had similar error rates and one group switched to e-prescriptions while the other continued with hand-written prescriptions. One year later, the number of errors was measured. The results are given in the two-way table.

	Error	No Error
Written	1478	2370
Electronic	254	3594

Give your answers to questions b) through e) in the form of a fraction.

a). Fill in the row and column totals.

b). What proportion of all the prescriptions had errors in them?

c). What proportion of electronic prescriptions had errors in them?

d). What proportion of written prescriptions had errors in them?

e). What proportion of the prescriptions with errors were electronic prescriptions?

Answer 1

(A)

	error	no error	total
Written	1478	2370	3848
Electronic	254	3594	3848
total	1732	5964	7696

(B) number of all the prescriptions had errors in them = 1732

total number of prescriptions = 7696

probability = (number of all the prescriptions had errors in them)/total number of prescriptions = 1732/7696 = 0.2251

(C) number of electronic prescriptions had errors in them = 254

total number of electronic prescriptions = 3848

probability = (number of electronic prescriptions had errors in them)/total number of electronic prescriptions = 254/3848 = 0.0660

(D) number of written prescriptions had errors in them = 1478

total number of written prescriptions = 3848

probability = (number of written prescriptions had errors in them)/total number of written prescriptions = 1478/3848 = 0.3841

(E) number of electronic prescriptions had errors in them = 254

total number of error prescriptions =1732

probability = (number of electronic prescriptions had errors in them)/total number of error prescriptions = 254/1732 = 0.1466