Here Are the Average Mathematics Achievement Scores for Ninth Graders

question 40

Multiple Choice

Here are the average mathematics achievement scores for ninth graders in 32 counties.Find the standard deviation. $$\begin{array} { l l l l l l l l } 599 & 585 & 574 & 572 & 569 & 565 & 564 & 551 \\539 & 534 & 531 & 528 & 525 & 524 & 519 & 501 \\488 & 480 & 478 & 475 & 471 & 465 & 458 & 443 \\427 & 410 & 409 & 389 & 380 & 382 & 355 & 314\end{array}$$

• A)75.3
• B)75
• C)73.3
• D)74.3
• E)75.5

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Definitions:

Experimenter Effects

Unintended influences that the experimenter's presence or actions may have on the results of an experiment.

Single-blind Studies

Experimental studies in which the participants do not know which experimental group they belong to (e.g., control or treatment), but the researchers do.

Dependent Variable

In an experiment, it is the variable that is tested and measured, expected to change as a result of manipulations of the independent variable.

Manipulates

To control or influence something or someone, often in a skillful manner and sometimes in a deceptive way.