Loading [MathJax]/jax/output/CommonHTML/jax.js

StatTutor Lesson - Significance Tests for a Proportion

true
Stat Tutor
true
true
You have completed 0 question sequences out of 12.
Video Player is loading.
Current Time 0:00
Duration 0:00
Loaded: 0%
Stream Type LIVE
Remaining Time 0:00
 
1x
    • Chapters
    • descriptions off, selected

      Question 1

      65

      Question 1.

      True or false: ˆp has an approximate Normal distribution with mean, p, and standard deviation, p(1p)n, when n is large.

      A.
      B.

      Incorrect. This is true provided np and n(1 - p) are both bigger than 10.
      Correct. This is true provided np and n(1 - p) are both bigger than 10.
      Incorrect. Try again.
      2

      Question 2

      70

      Question 2.

      What is the problem with the test statistic formula z=ˆppop(1p)n for testing the value of the parameter p?

      A.
      B.
      C.

      Incorrect. The problem is that we don't know the value of p. That's why we are performing a test of significance. Note: We can get the value of ˆp from the sample and the value of po from the null hypothesis.
      Correct. The problem is that we don't know the value of p. That's why we are performing a test of significance. Note: We can get the value of ˆp from the sample and the value of po from the null hypothesis.
      Incorrect. Try again.
      2

      Question 3

      225

      Question 3.

      What do we check to determine whether n is large enough for a good Normal approximation?

      A.
      B.
      C.

      Incorrect. Since we assume the null hypothesis to be true, we assume that p=po so we use po as the value of p whenever we need a value for p.
      Correct. Since we assume the null hypothesis to be true, we assume that p=po so we use po as the value of p whenever we need a value for p.
      Incorrect. Try again.
      2

      Question 4

      291

      Question 4.

      How should data be collected for a test on H0: p=po to be valid?

      A.
      B.
      C.
      D.

      Incorrect. Data should be collected with a simple random sample.
      Correct. Data should be collected with a simple random sample.
      Incorrect. Try again.
      2

      Questions 5-6

      332

      Question 5.

      The research question is, "Is the proportion of first-year students at this university who have "being very well-off financially" as an important personal goal significantly different from the national value of 73%?" What is the response variable and is it categorical or quantitative?

      A.
      B.
      C.

      Incorrect. The response variable is a measure on the individual. Each student is asked whether they feel "being very well-off financially is an important personal goal," so that is the response variable and it is categorical.
      Correct. The response variable is a measure on the individual. Each student is asked whether they feel "being very well-off financially is an important personal goal," so that is the response variable and it is categorical.
      Incorrect. Try again.
      2

      Question 7

      379

      Question 7.

      True or false: We use the symbol p in the hypotheses because the response variable is categorical and we want to test proportion.

      A.
      B.

      Incorrect. Whenever the response variable is categorical, we do inference on proportion.
      Correct. Whenever the response variable is categorical, we do inference on proportion.
      Incorrect. Try again.
      2

      Question 8

      407

      Question 8.

      What do we check to determine whether n is large enough for a good Normal approximation when computing P-value?

      A.
      B.
      C.

      Incorrect. Since we assume the null hypothesis to be true, we assume that p=po = 0.73 so we use po = 0.73 and check npo10 and n(1po)10 to see if n is large enough.
      Correct. Since we assume the null hypothesis to be true, we assume that p=po = 0.73 so we use po = 0.73 and check npo10 and n(1po)10 to see if n is large enough.
      Incorrect. Try again.
      2

      Question 9

      562

      Question 9.

      With P-value = 0.0258 and α = 0.05, should we reject H0?

      A.
      B.

      Incorrect. Because P-value = 0.0258 is less than α = 0.05, we reject H0.
      Correct. Because P-value = 0.0258 is less than α = 0.05, we reject H0.
      Incorrect. Try again.
      2

      Question 10

      577

      Question 10.

      Given that the hypotheses are H0: p = 0.73 and Ha: p 0.73 and we rejected H0, what should we conclude?

      A.
      B.
      C.

      Incorrect. Since we rejected H0, we conclude that Ha is correct. Thus the proportion differs significantly from 0.73.
      Correct. Since we rejected H0, we conclude that Ha is correct. Thus the proportion differs significantly from 0.73.
      Incorrect. Try again.
      2

      Question 11

      700

      Question 11.

      With 40 children having autism out of 6,000 children, what is ˆp?

      A.
      B.
      C.
      D.

      Incorrect. ˆp = 406000 = 0.0067
      Correct. ˆp = 406000 = 0.0067
      Incorrect. Try again.
      2

      Question 12

      762

      Question 12.

      How were the data collected for this study?

      A.
      B.
      C.

      Incorrect. All 6,000 three- to ten-year-olds in Brick Township were studied.
      Correct. All 6,000 three- to ten-year-olds in Brick Township were studied.
      Incorrect. Try again.
      2

      Question 13

      1066

      Question 13.

      What table is used to find the P-value for a test of significance on proportion?

      A.
      B.

      Incorrect. We use the standard Normal table to find the P-value for testing proportion.
      Correct. We use the standard Normal table to find the P-value for testing proportion.
      Incorrect. Try again.
      2