Suppose that a device advertised to increase a car's gas mileage really does not work. We test it on a small fleet of cars (with $\mathrm { H } _ { 0 }$ : not effective), and our data results in a $P$-value of $0.004$. What probably happens as a result of our experiment?
A) We fail to reject $\mathrm { H } _ { 0 }$, committing Type II error.
B) We correctly fail to reject $\mathrm { H } _ { 0 }$.
C) We reject $\mathrm { H } _ { 0 }$, making a Type I error.
D) We reject $\mathrm { H } _ { 0 }$, making a Type II error.
E) $\mathrm { We }$ correctly reject $\mathrm { H } _ { 0 }$.

Question

Quizplus · Accepted Answer

A low P-value (0.004) suggests strong evidence against $\mathrm { H } _ { 0 }$, leading us to reject it, but since $\mathrm { H } _ { 0 }$ is true, this results in a Type I error.

Suppose That a Device Advertised to Increase a Car's Gas H0\mathrm { H } _ { 0 }H0​

Suppose That a Device Advertised to Increase a Car's Gas $\mathrm { H } _ { 0 }$