Bullying, "according to noted expert Dan Olweus, "poisons the educational environment and affects the learning of every child." Bullying and victimization are evident as early as preschool, with the problem peaking in middle school. Suppose you are interested m the emotional well-being of not only the victims but also bystanders, bullies, and those who bully but who are also victims (bully-victims). You decide to measure depression in a group of victims and a group of bully-victims using an 18-item. 5-point depression scale. Assume scores on the depression scale are normally distributed and that the variances of the depression scores are the same among victims and bully-victims. The group of 23 victims scored an average of 40.1 with a sample standard deviation of 10 on the depression scale. The group of 28 bully-victims scored an average of 46.8 with a sample standard deviation of 11 on the same scale. You do not have any presupposed assumptions about whether victims or bully-victims will be more depressed, so you formulate the null and alternative hypotheses as:.
H0:μvictims - μ bully victims = 0
H1:μvictims - μ bully victims ≠ 0
You conduct an independent-measures t test. Given your null and alternative hypotheses, this is a test.
To use the Distributions tool to find the critical region, you first need to set the degrees of freedom.

Exercise 18-15 sheffield appliance center is an experienced home appliance dealer. sheffield appliance center also offers a number of services for the home appliances that it sells. assume that sheffield appliance center sells ovens on a standalone basis. sheffield appliance center also sells installation services and maintenance services for ovens. however, sheffield appliance center does not offer installation or maintenance services to customers who buy ovens from other vendors. pricing for ovens is as follows. oven only $790 oven with installation service 850 oven with maintenance services 970 oven with installation and maintenance services 990 in each instance in which maintenance services are provided, the maintenance service is separately priced within the arrangement at $180. additionally, the incremental amount charged by sheffield appliance center for installation approximates the amount charged by independent third parties. ovens are sold subject to a general right of return. if a customer purchases an oven with installation and/or maintenance services, in the event sheffield appliance center does not complete the service satisfactorily, the customer is only entitled to a refund of the portion of the fee that exceeds $790. assume that a customer purchases an oven with both installation and maintenance services for $990. (b) indicate the amount of revenue that should be allocated to the oven, the installation, and to the maintenance contract.

Stocks a, b, and c are similar in some respects: each has an expected return of 10% and a standard deviation of 25%. stocks a and b have returns that are independent of one another; i.e., their correlation coefficient, r, equals zero. stocks a and c have returns that are negatively correlated with one another; i.e., r is less than 0. portfolio ab is a portfolio with half of its money invested in stock a and half in stock b. portfolio ac is a portfolio with half of its money invested in stock a and half invested in stock c. which of the following statements is correct? a. portfolio ab has a standard deviation that is greater than 25%.b. portfolio ac has an expected return that is less than 10%.c. portfolio ac has a standard deviation that is less than 25%.d. portfolio ab has a standard deviation that is equal to 25%.e. portfolio ac has an expected return that is greater than 25%.

Sauer food company has decided to buy a new computer system with an expected life of three years. the cost is $440,000. the company can borrow $440,000 for three years at 14 percent annual interest or for one year at 12 percent annual interest. assume interest is paid in full at the end of each year. a. how much would sauer food company save in interest over the three-year life of the computer system if the one-year loan is utilized and the loan is rolled over (reborrowed) each year at the same 12 percent rate? compare this to the 14 percent three-year loan.