Standards in Focus:
0 7.SP.6 - We need to be able to approximate the
chance event. First, we will be collecting data from
running multiple tests and recording the frequency
of the event. Then, we will take our findings to
predict the relative frequency given the probability.
0 7.SP.8a
0 7.SP.8b
Standards in Focus:
0 7.SP.6
0 7.SP.8a – We need to understand that, just as with
simple events, the probability of a compound event
is the fraction of outcomes in the sample space for
which the compound event occurs.
0 7.SP.8b
Standards in Focus:
0 7.SP.6
0 7.SP.8a
0 7.SP.8b – We need to know how to represent
sample spaces for compound events using methods
such as organized lists, tables, and tree diagrams.
Here’s the situation:
Bill’s sock drawer contains 2 blue socks, 2
green socks, and 2 red socks. If he picks one
sock at random, what is the probability it will
be blue? If he then picks another sock
(without returning the first sock), what is the
probability the second sock will be blue?
What is the probability that both socks will be
blue?
Do this…
0 Each bag has 2 blue, 2 green, and 2 red cubes to
represent Bill’s socks.
0 One person should pick a cube at random.
0 The other person should record the color on the 30trial recording chart.
0 DON’T RETURN THE CUBE TO THE BAG!
0 Select another cube at random. Record its color.
0 Return the two cubes to the bag.
0 Repeat this procedure 30 times.
st
1
Period
1. Mari & Deajah
2. Trent & Christian
3. Breanna, Nyla &
4.
5.
6.
7.
8.
9.
Jamia
Brandon & Ke’Luhv
Kelleah & Tattiana
Arian & Kyle
James & Logan
Nolan & Damir
Jordyn & Kaitlin
4th Period
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Westina & Denaji
John & Parker
Landen & Austin
Treyton & Gerald
Daniel & Alexander
Hailey & Breyana
Mikey & Angel
Jorden & Ricardo
Ericka & Haley
Taylor & Jireh
Gabrielle & Cyanna
Stacey & Elana
Novalee, Destiny, &
Ashley
Determine the probability…
0 What’s the probability of randomly choosing a blue
sock from the sock drawer?
0 IF the first sock chosen is blue, what’s the probability
of choosing a second blue sock from the drawer?
0 REMEMBER: the first blue sock wasn’t replaced. What
effect does that have on your experiment?
Conditional Probability
The formula for a conditional probability:
P(B,B) = 1/3 x 1/5
P(B,B) = 1/15