Question

A random sample of 15 chemists from Washington state shows an average salary of $46613 with a standard deviation of $775. A random sample of 24 chemists from Florida state shows an average salary of $47757 with a standard deviation of $872. A chemist that has worked in both states believes that chemists in Washington make a different amount than chemists in Florida. At α α =0.01 is this chemist correct? Let Washington be sample 1 and Florida be sample 2. The correct hypotheses are: H 0 : μ 1 ≤ μ 2 H 0 : μ 1 ≤ μ 2 H A : μ 1 > μ 2 H A : μ 1 > μ 2 (claim) H 0 : μ 1 ≥ μ 2 H 0 : μ 1 ≥ μ 2 H A : μ 1 < μ 2 H A : μ 1 < μ 2 (claim) H 0 : μ 1 = μ 2 H 0 : μ 1 = μ 2 H A : μ 1 ≠ μ 2 H A : μ 1 ≠ μ 2 (claim) Correct

Since the level of significance is 0.01 the critical value is 2.736 and -2.736

The test statistic is: Incorrect(round to 3 places)

The p-value is: Incorrect(round to 3 places)

A custodian wishes to compare two competing floor waxes to decide which one is best. He believes that the mean of WaxWin is less than the mean of WaxCo.

In a random sample of 12 floors of WaxWin and 16 of WaxCo. WaxWin had a mean lifetime of 25.5 with a standard deviation of 6.7 and WaxCo had a mean lifetime of 30.4 with a standard deviation of 10.6. Perform a hypothesis test using a significance level of 0.05 to help him decide.

Let WaxWin be sample 1 and WaxCo be sample 2

The correct hypotheses are:

• H0:μ1≤μ2H0:μ1≤μ2
  HA:μ1>μ2HA:μ1>μ2(claim)
• H0:μ1≥μ2H0:μ1≥μ2
  HA:μ1<μ2HA:μ1<μ2(claim)
• H0:μ1=μ2H0:μ1=μ2
  HA:μ1≠μ2HA:μ1≠μ2(claim)

Since the level of significance is 0.05 the critical value is -1.707
The test statistic is: (round to 3 places)
The p-value is: (round to 3 places)

A researcher is interested in seeing if the average income of rural families is greater than that of urban families. To see if his claim is correct he randomly selects 20 families from a rural area and finds that they have an average income of $66691 with a standard deviation of $794. He then selects 12 families from a urban area and finds that they have an average income of $69126 with a standard deviation of $978. Perform a hypothesis test using a significance level of 0.01 to help him decide.

Let the rural families be sample 1 and the urban families be sample 2.

The correct hypotheses are:

• H0:μ1≤μ2H0:μ1≤μ2
  HA:μ1>μ2HA:μ1>μ2(claim)
• H0:μ1≥μ2H0:μ1≥μ2
  HA:μ1<μ2HA:μ1<μ2(claim)
• H0:μ1=μ2H0:μ1=μ2
  HA:μ1≠μ2HA:μ1≠μ2(claim)

Since the level of significance is 0.01 the critical value is 2.532
The test statistic is: (round to 3 places)
The p-value is: (round to 3 places)

Answer 1