A design engineer wants to construct a sample mean chart for controlling the service life of a halogen headlamp his company produces. He knows from numerous previous samples that this service life is normally distributed with a mean of 500 hours and a standard deviation of 20 hours. On three recent production batches, he tested service life on random samples of four headlamps, with these results:

Apsychologist has developed a series of personality inventories and wants to determine if they are valid. one of the scales measures perfectionism, so he asks a colleague for advice on how to establish the validity of this scale. the colleague tells him that if he were to find a sample of people with personality disorder, these people would obtain high scores on a scale that measures perfectionism.

Aresearcher is studying women recently admitted to a state prison. all potential subjects must have children under the age of five. research subjects will be given a basket of toys to use at their children’s first visit that the children can then take home. in assessing this proposal, the irb needs to determine that the toys are: age appropriate.not an excessive incentive.educational.of high quality.

True or false: the eastern roman empire lasted for 1,000 years longer than the western roman empire.