The Next Few Questions Refer to the Following Description and Table

question 7

Multiple Choice

The next few questions refer to the following description and table.
Diatoms are encased in Petri-platelike cases (valves) made of translucent hydrated silica whose thickness can be varied. The material used to store excess calories can also be varied. At certain times, diatoms store excess calories in the form of the liquid polysaccharide, laminarin, and at other times as oil. The following are data concerning the density (specific gravity) of various components of diatoms, and of their environment.
Specific Gravities of Materials Relevant to Diatoms

-Judging from the table and given that water's density and, consequently, its buoyancy decrease at warmer temperatures, in which environment should diatoms (and other suspended particles) sink most slowly?

• A)cold fresh water
• B)warm fresh water
• C)cold sea water
• D)warm sea water
• E)warm brackish water

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Definitions:

Z-Test

A statistical test used to determine whether two population means are different when the variances are known and the sample size is large.

Degrees of Freedom

The total number of independent pieces of information that went into the estimation of a parameter or the calculation of a statistic.

Chi-Squared Table Value

A value derived from the chi-squared distribution used in statistical tests to determine the significance of observed data.

Test Statistic

A calculated value from sample data used to make decisions about a hypothesis, indicating whether to reject the null hypothesis.