P Value Standard Error Sampling Distribution Stats Solved Practice

Progress Check

Use this activity to assess whether you and your peers can:

• Explain the meaning of each relevant item from the StatCrunch output when testing a claim about a mean.

Learn by Doing

This activity gives you practice explaining the different parts of the StatCrunch print-out for a hypothesis test for a population mean. You will review the meaning of standard error, T-scores and the P-value.

Some features of this activity may not work well on a cell phone or tablet. We highly recommend that you complete this activity on a computer.

Use the rubric at the bottom of this page as a guide for completing this assignment.

A list of StatCrunch directions is provided after the Prompt section below.

Directions

Submit your work:

• Commit a good-faith effort to address all items in the Prompt section below. Please be sure to number your responses.

Complete your assigned peer reviews:

• After you submit your initial good-faith attempt, continue to the ANSWER(S) page and review your instructor’s response. But please do not submit your corrected work yet.
• Within three days after the due date, return to this assignment and complete your assigned peer reviews (directions (Links to an external site.)).

Submit your corrected work:

• We all learn from mistakes (our own and our classmates’ mistakes). So please do not immediately correct your own mistakes. If possible, wait until you receive feedback from at least one of your peers.
• If necessary, correct your work and resubmit the entire assignment. Your instructor will only review and grade your most recent submission, so please do not refer to a previous submission.

Prompt

1. In a previous lab we tested the following hypotheses, 0$H_0$: =4.73$\mu =4.73$ and $H_a$: <4.73$\mu <4.73$ (where $\mu$ is the mean number of alcoholic drinks consumed by students at a liberal arts college).

   In a random sample of 75 students, the mean was 3.93 alcoholic drinks consumed in a week. Here is the StatCrunch output from the hypothesis test.
   $\mu$: Mean of variable
   0$H_0$: =4.73$\mu =4.73$
   $H_A$: ≠4.73$\mu \ne 4.73$

   Hypothesis test results

   Variable	Sample Mean	Std. Err.	DF	T-Stat	P-value
   number of drinks per week	3.9333333	0.43592434	74	-1.8275343	0.0717

   Using this context and the StatCrunch output, explain the meaning of each of the following.

   1. Std. Err (standard error)
   2. T-stat (T-score)
   3. P-value
2. In a previous matched pairs lab we tested the following hypotheses, where $\mu$ is the mean of the differences in corn yield for a plot of land (regular seed minus kiln-dried): H0: µ = 0 and Ha: µ < 0. In a random sample of 11 seeds of each type, the mean of the differences in the sample was -33.7. Here is a StatCrunch print-out of the hypothesis test.

   Paired T hypothesis test:
   = 1− 2${\mu }_D={\mu }_1-{\mu }_2$: Mean of the difference between Regular seed and Kiln-dried seed
   0$H_0$: =0${\mu }_D=0$
   $H_A$: <0${\mu }_D<0$

   Hypothesis test results

   Difference	Mean	Std. Err.	DF	T-Stat	P-value
   Regular seed – Kiln-dried seed	-33.727273	19.951346	10	-1.6904761	0.0609

   Differences stored in column, Differences.

   Using this context and the StatCrunch output, explain the meaning of each of the following.

   1. Std. Err (standard error)
   2. T-stat (T-score)
   3. P-value.