Stat 10

You are constructing a 90% confidence interval for the difference of means from simplen random samples from two independent populations. The sample sizes are n1 = 6 and n2 =14. You draw dot plots of the samples to check the normality condition for two-sample tprocedures. Which of the following descriptions of those dot plots would suggest that it is safe to use t-procedures?

• I only

• II only

• III only

• I, II, and III

• t-procedures are not recommended in any of these cases.

Janice and her cousin Linda are a little competitive about the relative merits of their home towns. One contest they had was to determine who had more rainy days. They found weather records on the internet and each of them randomly selected 60 days from the past 5 years. Janice found that there had been measurable rainfall on 17 of the 60 days she selected for Asheville, and Linda found that there had been measurable rainfall on 12 of the 60 days she selected for Lincoln. They intend to perform a test of significance on their data, using the hypotheses Ho : pA − pL = 0 versus Ha : pA − pL ≠ 0 and the 0.05 significance level. Janice and Linda’s test statistic is 1.07. Which of the following is closest to the appropriate P-value for the test?

• 0.0446

• 0.0892

• 0.1423

• 0.1449

• 0.2846

Probability is defined as...

• the set of all possible outcomes.

• the chance that an event will happen.

• a tree diagram.

• the fundamental counting principle.

The chart below represents the number of marbles in a jar.
P(green) = 

• 5/19

• 10/28

• 5/14

What is the probability of spinning red?

• 0

• 1/2

• 3/4

• 1

Action: Roll a die

Event: Roll a number less than 4

Which outcomes are part of the event?

• 1, 2, 3, 4, 5, 6

• 1, 2, 3, 4, 5

• 1, 2, 3, 4

• 1, 2, 3

If you are picking a card randomly from a deck of cards, the events of picking a jack and picking a heart are ...

• Mutually Exclusive

• Not Mutually Exclusive

If you are picking a card randomly from a deck of cards, the events of picking an ace and picking a ‘3’ are ...

• Mutually Exclusive

• Not Mutually Exclusive

If you roll one die, what is the probability of getting an odd number or a 4?

• 2/3

• 1/3

• 1/2

• 1/6

A bag contains 9 green marbles, 5 yellow marbles and 6 red marbles.  You choose one marble.   What is the probability of selecting a green or red marble?

• 8/15

• 6/11

• 3/4

• 2/3