A Test of Spelling Ability Is Given to a Random

question 19

Short Answer

A test of spelling ability is given to a random sample of 10 students before and after they complete a spelling course.The mean score before the course was 119.60 and after the course the mean score was 130.80.The standard deviation of the difference is 16.061.Calculate the test statistic to test the claim that scores were higher after the course.

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Definitions:

Troposphere

The lowest layer of Earth's atmosphere where weather happens and where most of the atmospheric water vapor exists.

Troposphere

The troposphere is the lowest layer of Earth's atmosphere, where most weather phenomena occur, extending from the Earth's surface to about 8 to 15 kilometers above.

Stratosphere

The stratosphere is a layer of the Earth's atmosphere located above the troposphere, characterized by a slight temperature increase with altitude and the presence of the ozone layer.

Ozone

A molecule composed of three oxygen atoms, found in the Earth's stratosphere, where it plays a critical role in protecting living organisms from ultraviolet radiation.