Question

Suppose you just purchased a digital music player and have put 12 tracks on it. After listening to them you decide that you like 4 of the songs. With the random feature on your​ player, each of the 12 songs is played once in random order. Find the probability that among the first two songs played ​(a) You like both of them. Would this be​ unusual? ​(b) You like neither of them. ​(c) You like exactly one of them. ​(d) Redo​ (a)-(c) if a song can be replayed before all 12 songs are played.

Answer 1

Answer:

a) 9% , not unusual

b) 42.4%

c) 48.4%

d) 11.1% , 44.4% , 44.4%

Step-by-step explanation:

We have the following information from the statement:

n = 12

r = 4

a)  

P (likebothofthem) = P (likefirstsong) * P (likesecondsong)

P = 4/12 * 3/11

P = 0.09 = 9%

The probability is not unusual, unusual is considered less than 0.05 or 5%

b)

P (likeneither) = P (notlikefirstsong) * P (notlikesecondsong)

P = 8/12 * 7/11

P = 0.424 = 42.4%

c) P (likeexactlyoneofthem) = P (firstsongliked) * P (secondsongnotliked) + P (firstsongnotliked) * P (secondsongliked)

P = (4/12 * 8/11) + (8/12 * 4/11)

P = 0.484 = 48.4%

d)

a)

P (likebothofthem) = P (likefirstsong) * P (likesecondsong)

P = 4/12 * 4/12

P = 0.111 = 11.1%

The probability is not unusual, unusual is considered less than 0.05 or 5%

b)

P (likeneither) = P (notlikefirstsong) * P (notlikesecondsong)

P = 8/12 * 8/12

P = 0.444 = 44.4%

c) P (likeexactlyoneofthem) = P (firstsongliked) * P (secondsongnotliked) + P (firstsongnotliked) * P (secondsongliked)

P = (4/12 * 8/12) + (8/12 * 4/12)

P = 0.444 = 44.4%