In: Statistics and Probability
The table below shows a random sample of musicians and how they learned to play their instruments. Complete the empty cells of the table to answer the following questions.
Gender |
Self-Taught |
Learned in School |
Private Instruction |
TOTAL |
Female |
12 |
38 |
72 |
|
Male |
58 |
|||
TOTAL |
31 |
62 |
37 |
130 |
1. What is the probability of randomly selecting a musician who is female?
2.What is the probability of randomly selecting a musician who is a male AND had private instruction?
3. What is the probability of randomly selecting a musician who is a female OR one that is self-taught? (Hint: be careful not to double-count individuals who meet both criteria)
4. True or False: The events of "being a female musician" and "learning music in school" are mutually exclusive.
5. The events "being a female musician" and "learning music in school" are independent events.
table is
gender | Self-taught | Learned in school | private Instruction | Total |
male | 12 | 38 | 22 | 72 |
female | 19 | 24 | 15 | 58 |
total | 31 | 62 | 37 | 130 |
1.
probability of randomly selecting a musician who is female is given by
2.
P(musician who is a male AND had private instruction) = no. males with private instruction/N
=15/130=0.1154
3.
P(female) =0.5538
P( self taught) =n(self taught)/N =31/130=0.2385
P(female and self taught) =n( female and self taught)/N =12/130 =0.0923
P( female or self taught) =P(female)+P( self taught) -P( female and self taught)
=0.5538+0.2385-0.0923
=0.7
4.
since there is 38 females musicians who learned music in school hence these events can not be mutually exclusive.
Hence FALSE
5.
P( female and learned in school) =n( female and learned in school)/N =38/130 =0.2923
P(female) =0.5538
P(learned in school) =n(learned in school)/N =62/130=0.4769
now
P(female)*P(learned in school) =0.5538*0.4769=0.2641 not equal to P(female and learned in school)
Hence these events are not independent.