Ck Your Under... Mason never has a pencil when test day rolls around. Because the classmates are tired of
having to supply pencils for Mason, only 15% of students will give Mason a pencil when
asked. Today is test day and Mason begins asking randomly selected students for a pencil.
Let Y = the number of students Mason asks until he finds someone who will give him a
pencil.
1. Describe this probability distribution. Be sure to check the appropriate conditions.
|
2. What is the probability that the third person asked is the first person who gives
him a pencil?
1
3. What is the probability that Mason gets a pencil by the third person he would
ask?
4. How many people should Mason expect to ask before getting a pencil?
5. Should Mason be surprised if Mason didn't receive a pencil until he asked at
least 10 people? Calculate a probability to justify your answer.
6. Find the standard deviation for the distribution of the number of people he asks
for a pencil before finding someone who will give him one.