Exercise 1: (Binomial distribution) Use Table C
“A university that is better known for its basketball program than for its academic strength claims that 80% of its basketball players get degrees. An investigation examines the fate of all 20 players who entered the program over a period of several years that ended 6 years ago. Of these players, 11 graduated and the remaining 9 are no longer in school. If the university’s claim is true, the number of players who graduate among the 20 studied should have the B(20,0.8) distribution.
(a) Find the probability that exactly 11 of the 20 players graduate.
(b) Find the probability that 11 or fewer players graduate. This probability is so small that it casts doubts on the university’s claim.”
(Hint: In both questions, 11 graduating is the same as 9 failing when looking at 20 students. Failures have the B(20,0.2) distribution which is available in Table C).
Exercise 2:
A quiz has 25 multiple choice questions. Each question has 5 possible answers, one of which is correct. A correct answer is worth 4 points but a point is taken off for each wrong answer. Fill in the blanks below:
The score will be like the sum of_____________draws
from the box: |______________|.
Fill in the first blank with a number and the second with a box of tickets.
Explain your answers.
Exercise 3:
A student organization is planning to ask a sample of 50 students if they have noticed alcohol abuse brochures on campus. The sample percentage who say “Yes” will be reported. The organization’s statistical advisor says that the standard deviation of this percentage will be about 7%.
(a) What would the standard error be if the sample contained 100 students rather than 50?
(b) How large a sample is required to reduce the standard error of the percentage who say “Yes” from 7% to 3.5%? Explain to someone who knows no statistics the advantage of taking a larger sample in a survey of opinions.
Exercise 4: (#1 p.391)
The Residential Energy Consumption Survey found in 1990 that 14.8% of American households had a computer. A market survey organization repeated this study in a certain town with 25,000 households, using a simple random sample of 500 household: 79 of the sample households had computers.
(a) The percentage of households in the town with computers is estimated as:____________;
(b) this estimate is likely to be off by ___________ or so (this is the SE%).
Answers are on the bottom ... just needs checking thats all.... if there correct or not... thanks
“A university that is better known for its basketball program than for its academic strength claims that 80% of its basketball players get degrees. An investigation examines the fate of all 20 players who entered the program over a period of several years that ended 6 years ago. Of these players, 11 graduated and the remaining 9 are no longer in school. If the university’s claim is true, the number of players who graduate among the 20 studied should have the B(20,0.8) distribution.
(a) Find the probability that exactly 11 of the 20 players graduate.
(b) Find the probability that 11 or fewer players graduate. This probability is so small that it casts doubts on the university’s claim.”
(Hint: In both questions, 11 graduating is the same as 9 failing when looking at 20 students. Failures have the B(20,0.2) distribution which is available in Table C).
Exercise 2:
A quiz has 25 multiple choice questions. Each question has 5 possible answers, one of which is correct. A correct answer is worth 4 points but a point is taken off for each wrong answer. Fill in the blanks below:
The score will be like the sum of_____________draws
from the box: |______________|.
Fill in the first blank with a number and the second with a box of tickets.
Explain your answers.
Exercise 3:
A student organization is planning to ask a sample of 50 students if they have noticed alcohol abuse brochures on campus. The sample percentage who say “Yes” will be reported. The organization’s statistical advisor says that the standard deviation of this percentage will be about 7%.
(a) What would the standard error be if the sample contained 100 students rather than 50?
(b) How large a sample is required to reduce the standard error of the percentage who say “Yes” from 7% to 3.5%? Explain to someone who knows no statistics the advantage of taking a larger sample in a survey of opinions.
Exercise 4: (#1 p.391)
The Residential Energy Consumption Survey found in 1990 that 14.8% of American households had a computer. A market survey organization repeated this study in a certain town with 25,000 households, using a simple random sample of 500 household: 79 of the sample households had computers.
(a) The percentage of households in the town with computers is estimated as:____________;
(b) this estimate is likely to be off by ___________ or so (this is the SE%).
Answers are on the bottom ... just needs checking thats all.... if there correct or not... thanks