Anational health organization warns that 30% of middle school students nationwide have been drunk. concerned, a local health agency randomly and anonymously surveys 110 of the 1212 middle school students in its city. only 21 report having being drunk. is there any reason to believe that the national level of 30% is not true of the middle school students in this city?

Reliability and validity reliability and validity are two important considerations that must be made with any type of data collection. reliability refers to the ability to consistently produce a given result. in the context of psychological research, this would mean that any instruments or tools used to collect data do so in consistent, reproducible ways. unfortunately, being consistent in measurement does not necessarily mean that you have measured something correctly. to illustrate this concept, consider a kitchen scale that would be used to measure the weight of cereal that you eat in the morning. if the scale is not properly calibrated, it may consistently under- or overestimate the amount of cereal that’s being measured. while the scale is highly reliable in producing consistent results (e.g., the same amount of cereal poured onto the scale produces the same reading each time), those results are incorrect. this is where validity comes into play. validity refers to the extent to which a given instrument or tool accurately measures what it’s supposed to measure. while any valid measure is by necessity reliable, the reverse is not necessarily true. researchers strive to use instruments that are both highly reliable and valid.

Portia grant is an employee who is paid monthly. for the month of january of the current year, she earned a total of $8,388. the fica tax for social security is 6.2% of the first $118,500 earned each calendar year and the fica tax rate for medicare is 1.45% of all earnings. the futa tax rate of 0.6% and the suta tax rate of 5.4% are applied to the first $7,000 of an employee's pay. the amount of federal income tax withheld from her earnings was $1,391.77. what is the total amount of taxes withheld from the portia's earnings?

Consider the following two projects. both have costs of $5,000 in year 1. project 1 provides benefits of $2,000 in each of the first four years only. the second provides benefits of $2,000 for each of years 6 to 10 only. compute the net benefits using a discount rate of 6 percent. repeat using a discount rate of 12 percent. what can you conclude from this exercise?