W4 Midterm Business Statistics
There are 8 questions in total, each worth 12.5 points. Please upload your answers to the dropbox below.
The following shows the temperatures (high, low) and weather conditions in a given Sunday for some selected world cities. For the weather conditions, the following notations are used: c = clear; cl = cloudy; sh = showers; pc = partly cloudy.
- How many elements are in this data set?
- How many variables are in this data set?
- How many observations are in this data set?
- Name the variables and indicate whether they are categorical or quantitative.
A student has completed 20 courses in the School of Arts and Sciences. Her grades in the 20 courses are shown below.
- Develop a frequency distribution and a bar chart for her grades.
- Develop a relative frequency distribution for her grades and construct a pie chart.
The number of hours worked per week for a sample of ten students is shown below.
- Determine the median and explain its meaning.
- Compute the 70th percentile and explain its meaning.
- What is the mode of the above data? What does it signify?
You are given the following information on Events A, B, C, and D.
- Compute P(D).
- Compute P(A ∩ B).
- Compute P(A | C).
- Compute the probability of the complement of C.
- Are A and B mutually exclusive? Explain your answer.
- Are A and B independent? Explain your answer.
- Are A and C mutually exclusive? Explain your answer.
- Are A and C independent? Explain your answer.
- When a particular machine is functioning properly, 80% of the items produced are non-defective.
- If three items are examined, what is the probability that one is defective?
- Use the binomial probability function to answer this question.
The average starting salary of this year’s graduates of a large university (LU) is $20,000 with a standard deviation of $8,000. Furthermore, it is known that the starting salaries are normally distributed.
- What is the probability that a randomly selected LU graduate will have a starting salary of at least $30,400?
- Individuals with starting salaries of less than $15,600 receive a low income tax break. What percentage of the graduates will receive the tax break?
- What are the minimum and the maximum starting salaries of the middle 95.4% of the LU graduates?
A simple random sample of 6 computer programmers in Houston, Texas revealed the sex of the programmers and the following information about their weekly incomes.
- What is the point estimate for the average weekly income of all the computer programmers in Houston?
- What is the point estimate for the standard deviation of the population?
- Determine a point estimate for the proportion of all programmers in Houston who are female.
Students of a large university spend an average of $5 a day on lunch. The standard deviation of the expenditure is $3. A simple random sample of 36 students is taken.
- What are the expected value, standard deviation, and shape of the sampling distribution of the sample mean?
- What is the probability that the sample mean will be at least $4?
- What is the probability that the sample mean will be at least $5.90?