Math math302 - Study guides, Class notes & Summaries

1. Question: A large department store is curious about what sections of the store make the most sales. The manager has data from ten years prior that show 30% of sales come from Clothing, 25% Home Appliances, 18% Housewares, 13% Cosmetics, 12% Jewelry, and 2% Other. In a random sample of 550 current sales, 188 came from Clothing, 153 Home Appliances, 83 Housewares, 54 Cosmetics, 61 Jewelry, and 11 Other. At α=0.10, can the manager conclude that the distribution of sales among the departments ha...

1. Question: An adviser is testing out a new online learning module for a placement test. They wish to test the claim that on average the new online learning module increased placement scores at a significance level of α = 0.05. For the context of this problem, μD=μnew–μold where the first data set represents the new test scores and the second data set represents old test scores. Assume the population is normally distributed. 2. Question: A researcher is testing reaction times between the...

1. Question: The least squares regression line for a data set is yˆ=5+0.3x and the standard deviation of the residuals is 0.4. Does a case with the values x = 3.3, y = 7.2 qualify as an outlier? 2. Question: The least squares regression line for a data set is yˆ=5+0.3x and the standard deviation of the residuals is 0.52. Does a case with the values x = -1.59, y = 5.78 qualify as an outlier? 3. Question: The following data represent the weight of a child riding a bike and the rolling distance...

1. Question: An instructor wants to compare spread (variation) of final grades of students in her online class and face-to-face class. The instructor selects 10 students randomly from each class and the following table shows the final grades of those students. See Attached Excel for Data. 2. Question: The lengths (in kilometers) of rivers on the South Island of New Zealand that flow to the Tasman Sea are listed below. Find the variance. See Attached Excel for Data. Use the Excel function to fin...

1. Question: An instructor wants to compare spread (variation) of final grades of students in her online class and face-to-face class. The instructor selects 10 students randomly from each class and the following table shows the final grades of those students. See Attached Excel for Data. 2. Question: The lengths (in kilometers) of rivers on the South Island of New Zealand that flow to the Tasman Sea are listed below. Find the variance. See Attached Excel for Data. Use the Excel function to fin...

1. Question: Find the area under the standard normal distribution to the left of z = -1.05. Round answer to 4 decimal places. 2. Question: Arm span is the physical measurement of the length of an individual's arms from fingertip to fingertip. A man's arm span is approximately normally distributed with mean of 70 inches with a standard deviation of 4.5 inches. Find length in inches of the 99th percentile for a man's arm span. Round answer to 2 decimal places. 3. Question: Find P(-1.96 ≤ Z ...

1. Question: The least squares regression line for a data set is yˆ=5+0.3x and the standard deviation of the residuals is 0.4. Does a case with the values x = 3.3, y = 7.2 qualify as an outlier? 2. Question: The least squares regression line for a data set is yˆ=5+0.3x and the standard deviation of the residuals is 0.52. Does a case with the values x = -1.59, y = 5.78 qualify as an outlier? 3. Question: The following data represent the weight of a child riding a bike and the rolling distance...

1. Question: A dishwasher has a mean life of 11.5 years with an estimated standard deviation of 1.5 years ("Appliance life expectancy," 2013). Assume the life of a dishwasher is normally distributed. Find the number of years that the bottom 10% of dishwasher would last. Round answer to 2 decimal places. 2. Question: The size of fish is very important to commercial fishing. A study conducted in 2012 found the length of Atlantic cod caught in nets in Karlskrona to have a mean of 47.8 cm and a s...

1. Question: The population standard deviation for the height of college football players is 2.7 inches. If we want to estimate a 95% confidence interval for the population mean height of these players with a 0.65 margin of error, how many randomly selected players must be surveyed? 2. Question: The population standard deviation for the height of college basketball players is 2.9 inches. If we want to estimate a 99% confidence interval for the population mean height of these players with a 0.45...

1. Question: Suppose a random variable, x, arises from a binomial experiment. If n = 14, and p = 0.13, find the standard deviation. Round answer to 4 decimal places. 2. Question: A coin is flipped 30 times. Find σ². Round to 1 decimal place. 3. Question: It is known that 50% of adult workers have a high school diploma. If a random sample of 6 adult workers is selected, what is the probability that 3 or more of them have a high school diploma? 4. Question: Suppose a random variable, x, arise...