Hey everyone... just realized there is another page to myassignment! Seems I don
ID: 2952195 • Letter: H
Question
Hey everyone... just realized there is another page to myassignment! Seems I don't understand the last 2 questions of mystats assignment and could really use some help!They are:
One half percentof the population has a certain disease. A test is developed forthe disease. The test gives false positive 3% and a false negative2% of the time.
a) What is the probability that Joe (a rondom person) testspositive?
b)Joe just got the bad new that the test came back positive; whatis the probability that Joe has the disease?
A random variable X can assume 5 values: 0,1,2,3,4. A portion ofthe probability distribution is shown here:
X --> 0 1 2 3 4
p(X)->0.2 0.1 0.1 ? 0.3
a) Find p(3)
b) calculate the population mean, variance and standarddeviation.
c) what is the probability that x is greater than 1?
d)what is the probability that x is less than or equal to 2
e) what is the probability that x is less than 3 and greater than1?
thanks to anyone who can help!!
One half percentof the population has a certain disease. A test is developed forthe disease. The test gives false positive 3% and a false negative2% of the time.
a) What is the probability that Joe (a rondom person) testspositive?
b)Joe just got the bad new that the test came back positive; whatis the probability that Joe has the disease?
Explanation / Answer
test : positive: false positive .03 or positive.47 : negative: falsenegative .02 or negative .48 Joe has disease : ( tests positive) and has disease) or( testsnegative and it is a false negative)=.47+.02=.49 test results says joe has disease, Probability he has disease=.02/.5= 1/25v v X --> 0 1 2 3 4 p(X)->0.2 0.1 0.1 ? 0.3 a) Find p(3)= 1- P(not 3)=1-(.2+.1+.1+.3)= .3 b) calculate the population mean, variance and standarddeviation. sum x* p(x) for all x= 0*.2+1*.1+2*.1+3*.3+4*.3=.2+.3+.1+.9+1.2=2.7 is mean variance = sum (x-mean)2P(x)=(0-2.7)2.2+(1-2.7)2.1+(2-2.7)2.1+(3-2.7)2.3+(4-2.7)2.3..Usecalculator standard deviation=variance .. use calculator c) what is the probability that x is greater than 1?P(2,3,4)=.1+.3+.3= .7 d)what is the probability that x is less than or equal to 2..P(0,1,2)=.2+.1+.1=.4 9 e) what is the probability that x is less than 3 and greater than1?