Chapter 35 Multiple choice questions

. Which of the following statements about the F-test is incorrect?

The data sets differ if the calculated value of F is greater than F_critical.

The value of F depends on the populations' sizes, the degrees of freedom DF, and the type of test we perform.

The data sets do not differ if the calculated value of F is greater than F_critical.

The F-statistic is a good way of assessing the accuracy of the standard deviation.

. Which of the following is not assumed when using ANOVA?

The data set must be collected from one source.

The sample sets must be independent.

The population variances are equal.

The populations from which the samples derive follow a normal distribution.

. A pair of data sets have standard deviations of 0.343 and 0.363. What is the value of the F-statistic?

0.8932 (to 4 s.f.)

1.1200 (to 4 s.f.)

1.058 (to 4 s.f.)

0.9450 (to 4 s.f.)

. A pair of data sets have standard deviations of 0.443 and 0.563. What is the value of the F-statistic?

0.619 (to 3 s.f.)

0.786 (to 3 s.f.)

1.271 (to 3 s.f.)

1.615 (to 3 s.f.)

. Which of the following lists of variables is not suitable for an N-way ANOVA analysis?

Choice of crop; supplier of the seeds; type of fertilizer

Sales data; sales staff; retail sector

Chemical supplier; chemical yield; undergraduate class

Reaction yield; reaction temperature; reaction rate

. Look at the data in Worked Example 35.4. Which of the following statements is INCORRECT?

The means of the two techniques are the same.

The new method is less sensitive than the old method because s is smaller.

The standard deviation of the new method is lower than that of the older method.

The older method is more capable of distinguishing between samples than the new method.

. An analyst devises a new sensor for which the standard deviation of measurement is 2.51. The existing technique for measuring the same ion has a standard deviation of 5.22. Both techniques have 6 degrees of freedom. Calculate a value of F and compare it with the relevant value from Table 35.3, and comment: is the new technique different?

F = 2.08. The technique is not different.

F = 2.08. The technique is different.

F = 4.325. The technique is different.

F = 4.325. The technique is not different.

. Look at the grid in Worked Example 35.3. Then select the one INCORRECT statement.

Technique 1 is the best technique because the standard deviation is 0.

Technique 1 is ideal for analyses in which the same result is expected.

Technique 2 is ideal for analyses in which we expect random variations in quality, but the overall quality is unlikely to change much.

Technique 3 is ideal for analyses in which every sample is different.

. Which of the following lists of variables is unconnected and therefore suitable for an N-way ANOVA analysis?

Solvent permittivity; chemical yield; duration of reaction reflux

Gibbs function of reaction; reaction enthalpy; reaction yield

Solvent permittivity; ionic conductivity; extent of electrode corrosion

Name of reaction; source of reagents; method of quantifying the yield

. Look at the data grid in Worked Example 35.2. Choose the one statement that is INCORRECT.

The mean for silica 4 is the lowest.

The standard deviation for silica 1 is the highest.

Silica 4 is the best silica for separating mixtures because the mean adsorbent amount is the lowest.

The single highest adsorbent amount occurs for silica 2.

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