An Engineer Wants to Know If the Average Amount of Energy

question 20

Essay

An engineer wants to know if the average amount of energy used in his factory per day has changed since 2005.The factory used an average of 2,000 megawatt hours (mwh)per day prior to 2005.Since 2005,the engineer surveyed 400 days and found the average energy use was 2,040 mwh per day.Assume that the population standard deviation is 425 mwh per day.
a.Specify the null and alternative hypotheses to determine whether the factory's energy use has changed.
b.Calculate the value of the test statistic and the p-value.
c.At the 5% significance level,can you conclude that the energy usage has changed? Explain.

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Definitions:

Contingency Management

A behavior change strategy often used in therapy to reinforce positive behaviors and reduce undesirable ones through rewards or consequences.

Counterconditioning

A therapy technique used to replace an unwanted behavior or response with a desired one by associating the behavior with a new, more positive stimulus.

Cognitive Therapy

A form of psychotherapy that emphasizes the importance of changing maladaptive thinking patterns in order to change feelings and behaviors.

Beck

Aaron Beck, a psychiatrist known for developing Cognitive Therapy (CT), which later evolved into Cognitive Behavioral Therapy (CBT), focusing on identifying and changing negative thought patterns.