Unit 7 Quiz: Probability

Given the probability model in the table below, what is the expected value of the random variable?

  X        48          16        3

P(X)     0.1         0.3      0.6

• 14.2

• 4.67

• 11.4

• 7.5

If the expected value is negative, are you expected to win?

• yes
• no

Eva flips a coin. If she gets heads, she wins $4. If she gets tails, she loses $3. What is her expected value of a coin flip?

• $1

• $0.50

• -$0.50

• $0

In the Probability Distribution table to the right what is the P(8)?

• 0.21

• 0.4

• 1

• -.38

The Table show the distribution of TVs in students' homes:

Find P(x < 2)

The Table show the distribution of TVs in students' homes:

Find the probability of having at least 3 TVs

Students at North River High School are assigned to home rooms with 25 students each. You randomly select 4 homerooms and gather data from each of the 100 students in these classes.

What type of sampling method was used?

• Simple Random

• Cluster

• Stratefied

• Systematic

The manager of a supermarket wants to survey their customers about their opinions on a new coffee shop. To obtain the sample, the manager surveys every tenth person coming into the supermarket, starting from the third customer of the day. Which sampling method is used for this study?

• simple random sampling

• systematic random sampling

• stratified sampling

• clustered sampling

A mysterious card-playing squirrel offers you the opportunity to join in his game. The rules are:

• to play you must pay him 1$

• If you pick a face card from a shuffled deck of cards, you win 6$.

(there are 12 face cards out of 52 cards)

Find the expected value you with per game?

• $0.38

• $6

• $0.62

• $1.68

Is this a Statistical Question or Not...?

What are the heights of all teachers at Union Elementary?

• Statistical

• Not statistical