Sociology Motherinlaw Sociologist say that 90 of married wom

Sociology: Mother-in-law Sociologist say that 90% of married women claim that their husband\'s mother is the biggest bone of contention in their marriages (sex and money are lower-rated areas of contintion). Suppose that six married women are having coffee together one morning. What is the probabiltiy that

a) all of them dislike their mother-in-law?

b) none of them dislike their mother-in-law?

c) at least four of them dislike their mother-in-law?

d) no more than three of them dislike their morther-in-law?

2. Psychology: Myers-Briggs Approximately 75% of all maketing personnel are extroverts, whereas about 60% of all computer programmers are introverts (Sources: A Guide to the Development and Use of Myers-Briggs Type Indicator, by Myers and McCaulley).

a) At a meeting of 15 marketing personnel, what is the probability that 10 or more are extroverts? What is the probability that 5 or more are extroverts? What is the probability that all are extroverts?

b) In a group of 5 computer programmers, what is the probability that none are introverts? What is the probability that none are introverts? What is the probability that 3 or more are introverts? What is the probability that all are introverts?

Solution

Let X be rv thatwomen like their mother in law.

then,X~Bin(6,0.1)

(a)P[X=6]=0.000001

(b)P[X=0]=0.531441

(c)P[X>=4]=0.00127

(d)P[X<=3]=0.99873

Let Y be a rv denoting the no. of extroverts among marketting personnel.

Y~Bin(15,0.75)

(a)P[Y>=10]=0.851632

P[Y>=5]=0.999885

P[Y=15]=0.0133635

Let Z be a rv denoting the no. of introverts among computer programmers.

Z~Bin(5,0.6)

(b)P[Z=0]=0.01024

P[Z>=3]=0.68256

P[Z=5]=0.07776