SOLUTION: An FBI survey showed that for about 80% of property crimes, criminals are never found and the case is never solved. Suppose that in a particular neighborhood there are repeated pr

Algebra.Com
Question 517777: An FBI survey showed that for about 80% of property crimes, criminals are never found and the case is never solved. Suppose that in a particular neighborhood there are repeated property crimes. The police are investigating six property crimes in this neighborhood.
. what is the probability that none of the crimes will be solved? .028
b. what is the probability that at least one will be solved? .972
c. what is the probability that 4 or more will not be solved?
d. what is the expected number of crimes that will be solved and what is the std. deviation?

Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
An FBI survey showed that for about 80% of property crimes, criminals are never found and the case is never solved. Suppose that in a particular neighborhood there are repeated property crimes. The police are investigating six property crimes in this neighborhood.
----------------------------------------------
Binomial Problem with n = 6 and p(not solved) = 0.8 p(solved) = 0.2
-------
a. what is the probability that none of the crimes will be solved?
P(x = 0) = 0.8^6 = 0.2621
------------------------------------
b. what is the probability that at least one will be solved?
(x>= 1) = 1 - P(x = 0) = 1 - 0.2621 = 0.7379
c. what is the probability that 4 or more will not be solved?
P(4<= x <=6) = 1 - P(0<= x <=3) = 1 - binomcdf(6,0.8,3) = 0.9011
--------------------
d. what is the expected number of crimes that will be solved and what is the std. deviation?
---
E(x) = u = np = 6*0.2 = 1.2
std = sqrt[npq] = sqrt(1.2*0.8] = 0.9798
============================================
Cheers,
Stan H.
============

RELATED QUESTIONS

Does crime pay? The FBI Standard Survey of Crimes showed that for about 80% of all... (answered by robertb)
Can someone please show me how to solve this statistic? Thank you! Does crime pay? The (answered by ccs2011)
The FBI claims that about 80% of all property crimes, the criminals are never found and... (answered by stanbon)
The FBI Standard surgery of Crimes reports that 80% of all property crimes NEVER get... (answered by jim_thompson5910)
statistics show that 80% of crimes are never solved.suppose a neighborhood district in a... (answered by stanbon)
About 80% of property crimes are never solved. How many crimes will need to be under... (answered by Boreal)
Vocabulary; The ? Of an event is never grater than 1 and never less than... (answered by richwmiller)
3. A sample of consumers was surveyed regarding their visits to a computer chain store... (answered by stanbon)
can you please show me how to work out this problem: Suppose that V(x) represents the... (answered by adamchapman)