Identify the response variable and whether the setting involves a single sample, a matched pairs, or two independent samples. a. A chemist obtains a reference specimen of known concentration from the National Institute of Standards and Technology. She then makes 20 measurements of the concentration of this specimen with the new method and checks for bias by comparing the mean result with the known concentration.
b. Choose 40 romantically attached couples in their midtwenties. Interview the man and woman separately about a romantic attachment they had at age 15 or 16. Compare the attitudes of men and women.
c. Another chemist is checking the same new method. He has no reference specimen, but a familiar analytic method is available. He wants to know if the new and old methods agree. He takes a specimen of unknown concentration and measures the concentration 10 times with the new method and 10 times with the old method.

1. single sample design

2. matched pairs

3. two independent samples.

Step-by-step explanation:

the response variable is known as the dependent variable, it is the variable that the researcher is interested i finding. the response variable is the x variable that responds to changes in the independent variable.

1.

In this question the researcher has only one sample that is the specimen. that is the reference specimen that she obtained. Therefore it is a single sample design.

the response variable here is the measurement of concentration.

2. In this question we have two pairs, men and women. The researcher is interested in comparing attitudes as she interviews them. so response variable is attitude or behavior

3. this is a 2 independent sample design. The researcher is using two different methods to test and their average is being compared.

a is the correct

step-by-step explanation:

given that there are two triangles j'k'l' and jkl>

the former is got by dilating the second one.

when drawn on a grid, (graph paper) coordinates of vertices of first triangle is

(6,12)j, (9,6)k and (12,9)l

side jk has length = distance between j and k

=

side j'k'=distance between j' and k'

=

ie j'k'l' has sides 1/3 of that of corresponding sides of jkl.

hence scale factor of 1/3 is used to get j'k'l'from jkl