stat-200-level-1
Question 1
A car painting company has determined that the painting time of cars is uniformly distributed between 25 and 105 minutes. What is the probability that it will take between 40 and 65 minutes for that company to paint a car ?
Question 2
The waiting times at a certain bus station are uniformly distributed between 7 and 15 minutes. What is the probability of waiting between 9 and 11 minutes ?
Question 3
The cooking time for a dish is uniformly distributed between 10 and 20 minutes. What is the probability that the cooking will take between 14 and 16 minutes ?
Question 4
A car painting company has determined that the painting time of cars is uniformly distributed between 30 and 105 minutes. What is the probability that this company will take less than 1 hour to paint a car ?
Question 5
The baking time for a cake is uniformly distributed between 10 and 18 minutes. What is the probability that the baking process takes more than 14 minutes ?
Question 6
The driving time for an individual from his home to his office is uniformly distributed between 20 minutes and 1 hour. Compute the probability that this individual takes more than half an hour to drive from home to office.
Question 7
The baking time for a cake is uniformly distributed between 10 and 18 minutes. What is the probability that the baking process takes more than 14 minutes ?
Question 8
The following graph represents a ____________ distribution.
Question 9
The area under the graph of a ____________ is equal to ____________.
Question 10
The graph of a ____________ distribution has the shape of a rectangle. The graph of a ____________ distribution has the shape of a bell.
Question 11
A) The following graph represents a ____________ probability distribution.
B) The following graph represents a ____________ probability distribution.
Question 12
The ACT scores of students are normally distributed with a mean of 18 and a standard deviation of 6. What percentage of students score between 10 and 15 ?
Question 13
The grades of students in an exam are normally distributed with a mean of 75 and a standard deviation of 5. What percentage of grades are between 72 and 90 ?
Question 14
A tea bag packing machine manufactures bags of tea whose weights are normally distributed with a mean of 250 g and a standard deviation of 2.5 g. What percentage of tea bags weight less than 245 g ?
Question 15
The fuel efficiency of a particular model of car is normally distributed with a mean of 28 miles/gallon and a standard deviation of 2 miles/gallon. What percentage of cars of that model have a fuel efficiency below 25 miles/gallon ?
Question 16
Assume that the heights of women are normally distributed with a mean of 65 inches and a standard deviation of 3 inches. If a woman is randomly selected , what is the probability that she is taller than 70 inches ?
Question 17
The grades of students on a test are normally distributed with a mean of 70 and a standard deviation of 8. What percentage of students scored more than 75 in the test ?
Question 18
The Normal Probability Distribution is an example of a ____________ probability distribution.
Question 19
The salaries of teachers in a particular school district are normally distributed with a mean of $ 50,000 and a standard deviation of $ 2,500. Due to budget limitations, teachers in the top 2 % of salaries will not get a raise. What is the cutoff salary ( rounded to the nearest dollar ) that separates the teachers that get the raise from those that don’t get the raise ?
Question 20
In a cookie factory, the masses of cookies are normally distributed with a mean of 40 g and a standard deviation of 2 g. If the 5 % heaviest cookies are rejected, what is the least weight for a cookie to be rejected ?