Test 2

Which one of the following is true about a random variable?

A random variable is a numerical measure of the outcome from a probability experiment, so its value is determined by chance.

Which of the following events are not disjoint?

A student is selected from a class of 30 students. E1=the student is a female. E2=the student is older than 20 year.

Which of the following statements is true about the sum rule of probability?

If two events A and B are disjoint, then P(A or B)=P(A)+P(B)

If E and F are two events, what is the probability of E and F?

None of the above

If E and F are independent events, then

P(E and F)=P(E).P(F)

The probability that two event E and F both occur is

P(E and F)=P(E)P(F|E)

Which of the following is true about the probability of an event E?

P(E)+P(Ec}=1, where Ec, complement of E, is the event that E does not occur.

Which one of the following statements is true about the probability of an event?

Probability is a measure of the likelihood of a random phenomenon or chance behavior occurring.

Consider a probability experiment of flipping two coins. What does the sample space S look like?

S={HH, HT, TT}

Which one of the following statement is not correct?

Suppose you draw a card from a standard 52-card deck of cards and then roll a die. The events "draw a heart" and "roll an even number" are not independent.

Which of the following statements is correct?

The least-squares regression line minimizes sum of the squared residuals

Which one of the following statements is true?

The number of light bulbs that burn out in a room of 10 light bulbs in the next year is a discrete variable and the possible values are: x = 0, 1, 2, ..., 10

Which one of the following statements is not true about the binomial experiment?

The probability of success for each trial is different.

What is the formula of computing probabilities using the classical method?

P(E)=(Number of ways E can occur)/(number of possible outcomes)

What is the formula of approximating probabilities using the Empirical approach?

P(E)=relative frequency of

Which of the following statements is true for the independent events E and F?

P(F)=P(F|E)

If E and F are any two events, which one of the following is correct about the probability of the event F given the event E has already occurred?

P(F|E)=P(E and F)/P(E)

Which one of the following is not correct?

P(at least one)=1-P(none)

Which one of the following statements is true about a discrete random variable?

The values of a discrete random variable can be plotted on a number line with space between each point.

What is the law of large numbers?

As the number of repetitions of a probability experiment increases, the proportion with which a certain outcome is observed gets closer to the probability of the outcome