Download 10/24 Intro to Probability HW

FST 10/24/16
Probability HW
1.
Name: ______________
Consider the experiment of tossing 3 fair coins (fair means that each side has a 50% chance of
occurring).
a.
Give the sample space.
b.
What is P(2 heads)?
c.
True or False: P(3 heads) = P(0 heads)
d.
What is P(at least 2 heads)?
2.
Give an example of an event G such that P(G) = 1.
3.
Let A be an event such that P(A) = 0.25. If there are 200 equally likely outcomes in the sample space,
how many outcomes are in A?
4.
A tetrahedral die has faces with the numbers 1, 3, 5, 7. Two of these dice are tossed. Find each
probability.
a.
5.
P(sum is even)
b.
P(sum is odd)
c.
P(sum is 8)
Probability can also be extended to infinite sample spaces. If each outcome in an infinite sample space
is equally likely and E is in that sample space then:
6.
a.
A clock stops at the time 2:13, so both hands are between the 2 & the 3. If the times are equally
likely, what is the probability that both hands stop between two consecutive numbers?
b.
If you consider the minute hand as a spinner and the face of the clock as the fair sample space,
what is the probability that the hand would land between the 6 and the 8?
Match each value of the probability of some event E with the statement that best explains how likely
event is to occur. Statements can be used more than once.
P(E) = 0
a.
b.
c.
d.
P(E) = 0.01
P(E) = 0.3
P(E) = 0.6
E cannot occur
E is certain to occur
E is unlikely to occur, but will occur once in a while in a long sequence of trials
E will occur more often than not
P(E) = 1