Which test is especially useful when the sample size is less than 30 and the population standard deviation is unknown?

Which of the following is true of businesses with a strong customer focus?

A) A customer-focused business lacks a long-term perspective. B) A customer-focused business realizes higher profits over the short-term. C) In a customer-focused business, shareholders are more interested in long-run survival than immediate earnings. D) In a customer-focused business, managers are usually judged on the last quarter's results, and not not on their efforts to ensure the long-run survival of the business. E) A customer-focused business is in synch with customers' needs and requirements, not with competitors' strategies.

Which of the following statements is true of a laboratory experiment?

A) It takes place in a realistic environment. B) It has low internal validity. C) The experimenter cannot control the environment easily. D) It has low external validity.