Computer keyboard failures are due to faulty electrical connects (12%) or mechanical defects (88%). Mechanical defects are related to loose keys (27%) or improper assembly (73%). Electrical connect defects are caused by defective wires (35%), improper connections (13%), or poorly welded wires (52%). a) Find the probability that a failure is due to loose keys. b) Find the probability that a failure is due to improperly connected or poorly welded wires.

a) 23.76%

b) 7.8%

Step-by-step explanation:

a) probability that a failure is due to loose keys.

loose key failure (27%) comes under mechanical failure (88%)

hence, probability that a failure is due to loose keys = 0.27*0.88 = 0.2376 = 23.76%

b) probability that a failure is due to improperly connected wire which comes under electrical failure = 0.12*0.13

probability that a failure is due to poorly welded wires which comes under electrical failure = 0.52*0.12

now, the probability that a failure is due to improperly connected or poorly welded wires. = 0.12 (0.52+0.13) = 0.078 = 7.8%

Probability that a failure is due to loose keys = 0.2376

Probability that a failure is due to improperly connected or poorly welded wires 0.078

Step-by-step explanation:

Given dа ta:

P (A) = percentage of faulty electrical connections is 12% = 0.12

P (B) = mechanical defects is 88% = 0.88

P (C / B) = percentage of defects that are related to loose keys is 27% = 0.27

P (D/B) = improper assembly is 73% = 0.73

P (E/A) = defective wires is 35% = 0.35

P (F/A) = improper connections is 13% = 0.13

P (G/A) = percentage of poorly welded wire is 52% = 0.52

a) Probability of being failure because of loose keys = 0.27/times 0.88 = 0.2376

b) Improperly connected = 0.13/times 0.12 = 0.0156

poorly welded wires = 0.52 / times 0.12 = 0.0624

Probability of being failure because of improperly connected or poorly welded wires = 0.0156 + 0.0624 = 0.078