Lecture05 - STAT 350 LECTURE 4 ANNOUNCEMENT Exams Date Exam...

STAT 350
L
ECTURE
4

A
NNOUNCEMENT

Exams

Date:

Exam 1: Wednesday, February 16 2011

Exam 2: Thursday, April 07 2011

Time: 6:30 PM – 7:30 PM

Place: LYNN 1136

You may bring:

1 page (8 in x 11 in) single sided handwritten crib sheet

Calculator: same calculator policy as SAT test
( http://sat.collegeboard.com/register/sat-test-day-checklist )
o
WEDNESDAY (JAN 26) – Lecture (not lab)
o
FRIDAY (Jan 28) – Homework 2 due & quiz

E
XAMPLE

Suppose we know that for a particular brand of
light bulb, the chance that a randomly selected
light bulb is defected is 0.1(i.e., defect rate is 0.1).
Now we check a batch of 4 of such light bulbs

What is the chance that we get no defected ones?

What is the chance that we get more than 3 defected?

What is the chance that we get less than 3 defected
ones?

E
XAMPLE

Suppose we know that for a particular brand of
light bulb, the chance that a randomly selected
light bulb is defected is 0.1(i.e., defect rate is 0.1).
Now we check a batch of 4 of such light bulbs

Solution: Let X be the number of defective bulbs

What is the chance that we get no defected ones?

P(X=0) = (0.9) 4

What is the chance that we get more than 3 defected?

P(X=4) = (0.1) 4

What is the chance that we get less than 3 defected
ones?