Binomial and Geometric Random Variables

If we want to calculate the probability of rolling a 6 for the first time on the 6^th roll of a die, would we use the geometric or the binomial distribution?

• geometric

• binomial

Which of the following is false about binomial probabilities?

• Their distributions are approximately symmetric.
• Trials must be fixed.
• Events musts be independent.
• The probability of success must be 0.50

When rolling a fair die 100 times, what is the probability of rolling a "4" exactly 25 times? Is this an example of binomial or geometric?

• binomial

• geometric

Which one of these variables is a continuous random variable?

• The time it takes a randomly selected student to complete an exam.
• The number of tattoos a randomly selected person has.
• The number of women taller than 68 inches in a random sample of 5 women. 
• The number of correct guesses on a multiple choice test. 

Which one of these variables is a discrete random variable?

• Time it takes a randomly selected student to complete a multiple choice exam.

• The heights of randomly selected students in the class.

• Distance between the students' home and school.

• Number of pairs of shoes a randomly selected person owns.

Is this binomial experiment? Shuffle a deck of 52 cards. Turn over the top card. Do not replace the card. Repeat the process 5 times. Let X = the card you observe.

• Yes
• No, the trials are not independent.
• No, there are more than 2 outcomes

Is this binomial experiment? Shuffle a deck of 52 cards. Turn over the top card. Put the card back in the deck, shuffle again. Repeat the process 50 times. Let X = the number of aces you observe.

• Yes
• No, the trials are not independent.
• No, there are more than 2 outcomes

Which of the following is NOT an assumption of the Binomial distribution?

• All trials must be independent.
• Each trial must be classified as a success or a failure.
• All trials are dependent on each other.
• The number of successes in the trials is counted.

If you want to know how many trials you will need before your first success, use the ????? model.

• Geometric

• Binomial

• Normal

• Calculator

If you want a certain number of successes in a set amount of trials, use the ????? model.

• geometric

• binomial

• normal

• calculato