Suppose the mean gpa of all students graduating from a particular university in 1975 was 2.30. the registrar plans to look at records of students graduating last year to see if the mean gpa has increased. define notation and state the null and alternative hypotheses for this investigation.

How can a poor housing market put home buyers in a financially unstable position? a. changing property values means it’s easier to find homes with low rental costs. b. when the home value decreases, property taxes and insurance costs increase. c. houses are valued lower than their purchase prices, so the home equity decreases. d. home buyers lose all tax benefits and tax incentives when the housing market goes down. e. mortgage payments can increase even though the home value decreases.

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.

Krier industries has just completed its sales forecasts and its marketing department estimates that the company will sell 43,800 units during the upcoming year. in the past, management has maintained inventories of finished goods at approximately 3 months' sales. however, the estimated inventory at the start of the year of the budget period is only 7,300 units. sales occur evenly throughout the year. what is the estimated production level (units) for the first month of the upcoming budget year?