In: Statistics and Probability
A statistics class for engineers consists of 53 students. The students in the class are classified based on their college major and sex as shown in the following contingency table:
|
College Major |
|||||
|
Sex |
Industrial Engineering |
Mechanical Engineering |
Electrical Engineering |
Civil Engineering |
Total |
|
Male |
15 |
6 |
7 |
2 |
30 |
|
Female |
10 |
4 |
3 |
6 |
23 |
|
Total |
25 |
10 |
10 |
8 |
53 |
If a student is selected at random from the class by the instructor to answer a question, find the following probabilities. Report your answer to 4 decimal places. (total 80 points)
Consider the following events:
A: The selected student is a male.
B: The selected student is industrial engineering major.
C: The selected student is civil engineering major.
D: The selected student is electrical engineering major.
Note: Indicate the type of probability as marginal, joint or conditional when asked.
Find the probability that the randomly selected student is a male. Indicate the type of probability. (8 + 2 = 10 points)
Find the probability that the randomly selected student is industrial engineering major. Indicate the type of probability. (8 + 2 = 10 points)
Find the probability that the randomly selected student is male industrial engineering major. Indicate the type of probability. (8 + 2 = 10 points)
Given that the selected student is industrial engineering major, what is the probability that the student is male? Indicate the type of probability.
(8 + 2 = 10 points)
Based on your answers on part a and d, are sex and college major of students in this class independent? Provide a mathematical argument? (6 points)
Consider the events A and B. Are sex and college major mutually exclusive events? Provide a mathematical argument to justify your answer. (6 points)
Find the probability that the randomly selected student is male or industrial engineering college major. (10 points)
Consider the events C and D. Are college major mutually exclusive events? Provide a mathematical argument to justify your answer. (6 points)
Find the probability that the randomly selected student is civil or electrical engineering college major. (6 points)
What is the probability that a randomly selected student is neither a male nor an industrial engineering college major? (6 points)
In: Statistics and Probability
SIU is a university in the UK catering for international students. There are currently 950 students. Fees were £16,000 for the last year and the president is concerned that adverse changes in the economic and educational environment are threatening the university’s future. The income of the market is expected to decline next year by 2%, and it is also expected that the average fee of competitive institutions will fall from £14,000 to £12,000. 10% of revenue is currently spent on promotion. The president does some research and estimates that the relevant demand elasticities are as follows:
PED = -1.6, YED = 2.2, AED = 1.8, CED = 0.8.
f. Briefly outline other marketing mix options for achieving the target (50 words
In: Economics
A random sample of 250 students at a university finds that these students take a mean of 15.7 credit hours per quarter with a standard deviation of 1.5 credit hours. Estimate the mean credit hours taken by a student each quarter using a 98% confidence interval.
In: Statistics and Probability
Students at a certain school were surveyed, and it was estimated that 19% of college students abstain from drinking alcohol. To estimate this proportion in your school, how large a random sample would you need to estimate it to within 0.08 with probability 0.99, if before conducting the study (a) you are unwilling to predict the proportion value at your school and (b) you use the results from the surveyed school as a guideline.
a. n=
b. n=
In: Statistics and Probability
2.5
7.In a survey of college students, each of the following was found. Of these students,
356356
owned a tablet,
294294
owned a laptop,
280280
owned a gaming system,
195195
owned a tablet and a laptop,
199199
owned a tablet and a gaming system,
137137
owned a laptop and a gaming system,
6868
owned a tablet, a laptop, and a gaming system, and
2626
owned none of these devices. Complete parts a) through e) below.
a) How many college students were surveyed?
(Simplify your answer.)
b) Of the college students surveyed, how many owned a tablet and a gaming system, but not a laptop?
(Simplify your answer.)
c) Of the college students surveyed, how many owned a laptop, but neither a tablet nor a gaming system?
(Simplify your answer.)
d) Of the college students surveyed, how many owned exactly two of these devices?
(Simplify your answer.)
e) Of the college students surveyed, how many owned at least one of these devices?
(Simplify your answer.)
4.
Thirty-five cities were researched to determine whether they had a professional sports team, a symphony, or a children's museum. Of these cities,
1919
had a professional sports team,
1717
had a symphony,
1414
had a children's museum,
1111
had a professional sports team and a symphony,
88
had a professional sports team and a children's museum,
66
had a symphony and a children's museum, and
44
had all three activities. Complete parts a) through e) below.
a) How many of the cities surveyed had only a professional sports team?
(Simplify your answer.)
b) How many of the cities surveyed had a professional sports team and a symphony, but not a children's museum?
(Simplify your answer.)
c) How many of the cities surveyed had a professional sports team or a symphony
(Simplify your answer.)
d) How many of the cities surveyed had a professional sports team or a symphony, but not a children's museum?
(Simplify your answer.)
e) How many of the cities surveyed had exactly two of the activities?
(Simplify your answer.)
3.2
7.
Construct the truth table for the compound statement q logical or left parenthesis p logical and tilde r right parenthesis .q ∨ (p ∧ ~r).
8.
Construct the truth table for the compound statement
left parenthesis p logical or tilde q right parenthesis logical or r(p ∨ ~q) ∨ r.
9.
Determine the symbolic form of the compound statement and construct a truth table for the symbolic expression. p ∨ (q ∨ r)
18.
Must the truth tables for
left parenthesis t logical and tilde s right parenthesis logical or tilde p(t ∧ ~s) ∨ ~p
and
left parenthesis s logical and tilde p right parenthesis logical or tilde t(s ∧ ~p) ∨ ~t
have the same number of trues in their answer columns?
Choose the correct answer below.
A.
Yes, because the two expressions have exactly the same form and each term can be T or F regardless of which letter is being used or whether it is negated or not.
B.
Yes, because the second expression contains the same three variables as the first expression.
C.
No, the truth table for the first expression has 5 trues and the truth table for the second expression only has 3 trues.
D.
No, because there is no relationship between the first expression and the second expression.
E.
Yes, because half the answers for each expression will be true and half will be false.
In: Advanced Math
In a large school, there are 60% students are athletes, 30% students in an honor program. 25% athlete students are in the honor program.
Let A = a randomly selected student is an athlete
B = a randomly selected student is in the honor program
Write the symbols of the following probabilities and find the value of the probabilities..
(a) The symbol for the probability a randomly selected athlete is in the honor program.
(b) The probability that a randomly selected student is an athlete and in the honor program.
(c) The probability that a randomly selected student is an athlete or is in the honor program.
(d) The probability that a randomly selected student is not an athlete.
In: Statistics and Probability
In: Statistics and Probability
10. The grades of students are normal distributed. In a class of 10 students the average grade on a quiz is 16.35, with a standard deviation of 4.15. ( 3 marks ) a) Find the 90% confidence interval for the population mean grade. b) If you wanted a wider confidence interval, would you increase or decrease the confidence level?
In: Statistics and Probability
Suppose that there are 100 students entering the Master’s of Business Administration program. Of these students, 20 have two years of work experience, 30 have three years of work experience, 15 have four years of work experience, and 35 have five or more years of work experience.
a) One of the students is selected at random. What is the probability that this student has at least three years of work experience?
b) The selected student has at least three years of work experience. What is the probability the student has four years of work experience?
c) Three students are selected at random. Calculate the probability that all three students have five or more years of work experience. Describe the key assumption required to make the calculation and comment on whether the assumption is reasonable.
d) Would it be reasonable to use the probability calculated in part a) as an estimate of the proportion of students entering the MBA degree program who have at least three years of work experience? Explain your answer. Limit your explanation to at most five sentences.
In: Math