19.   Medical Tests on Emergency Patients The frequency distribution shown here illustrates the number of medical tests conducted on 30 randomly selected emergency patients.

Number of tests              Number of

performed                    patients

 

0                                          12

1                                            8

2                                            2

3                                            3

4 or more                             5

If a patient is selected at random, find these probabilities.

a.     The patient has had exactly 2 tests done.

b.     The patient has had at least 2 tests done.

c.      The patient has had at most 3 tests done.

d.     The patient has had 3 or fewer tests done.

e.      The patient has had 1 or 2 tests done.