# statistics

### QNT 275 Final Exam 2017 – Probability Distribution Problems

For the probability distribution of a discrete random variable x, the sum of the probabilities of all values of x must be: Equal 1 Explanation: A sum of all values in a probability distribution will always add up to 1, period. The following table lists the probability [...]Read more

### QNT 275 Final Exam 2017 – Students Suffer from Math Anxiety

The following table gives the two-way classification of 500 students based on sex and whether or not they Suffer from Math Anxiety Sex – Yes – No Male – 168 – 72 Female – 167 – 93 If you randomly select one student from these 500 students, [...]Read more

### QNT 275 Final Exam 2017 – Seven Days of Summer in Los Angeles

The temperatures (in degrees Fahrenheit) observed during seven days of summer in Los Angeles are: 78, 99, 68, 91, 107, 75, 85 The range of these temperatures is: Find the range by subtracting the smallest number from the largest. 107 – 68 39 The variance of these temperatures, [...]Read more

### QNT 275 Final Exam 2017 – Cumulative Frequency Distribution of Commuting Time

The following table gives the cumulative frequency distribution of the commuting time (in minutes) from home to work for a sample of 400 persons selected from a city. Time (minutes) f 0 to less than 10 64 0 to less than 20 153 0 to less than 30 217 0 to less than 40 283 […]Read more

### QNT 275 Final Exam 2017 – Multiple Choice Study Guide

A quantitative variable is the only type of variable that can: assume numeric values for which arithmetic operations make sense Explanation: Quantitative values are numeric, while qualitative are labels, therefore, they are the only type that can perform arithmetic operations. A [...]Read more

### Hypothesis Test μ ≤ 10 – Solve Test Statistic

Given the following hypotheses: H0 : μ ≤ 10 H1 : μ > 10 A random sample of 10 observations is selected from a normal population. The sample mean was 12 and the sample standard deviation 3. Using the .05 significance level: Look closely at the formulas in the excel spreadsheet [...]Read more

### Hypothesis Test μ = 400 – Solve Test Statistic

Given the following hypotheses: H0 : μ = 400 H1 : μ ≠ 400 A random sample of 12 observations is selected from a normal population. The sample mean was 407 and the sample standard deviation 6. Using the .01 significance level: Setup the problem in excel and solve for the test [...]Read more

### Hypothesis Test United Nations Report – Solution Guide

A United Nations report shows the mean family income for Mexican migrants to the United States is $26,700 per year. A FLOC (Farm Labor Organizing Committee) evaluation of 21 Mexican family units reveals a mean to be $28,450 with a sample standard deviation of $10,850. Does this [...]Read more

### Hypothesis Test Rocky Mountain Rath Publishing – Solution Guide

The Rocky Mountain district sales manager of Rath Publishing Inc., a college textbook publishing company, claims that the sales representatives make an average of 36 sales calls per week on professors. Several reps say that this estimate is too low. To investigate, a random [...]Read more

### Hypothesis Test H0 : μ ≥ 220 – Solve Test Statistic and p-Value

The following information is available. H0 : μ ≥ 220 H1 : μ < 220 A sample of 64 observations is selected from a normal population. The sample mean is 215, and the population standard deviation is 15. Conduct the following test of hypothesis using the .025 significance level. [...]Read more