The diameters of bolts produced by a certain machine are r.v.'s dis- tributed as N(m, s2). In order for the bolts to be usable for the intended purpose, the s.d. s must not exceed 0.04 inch. A sample of size 16 is taken and is found that s = 0.05 inch. Formulate the appropriate testing hypothesis problem and carry out the test if a = 0.05.