Answered: A researcher is investigating whether a…

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

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Question

A researcher is investigating whether a reading intervention program improves reading comprehension for second graders. He collects a random sample of second graders and randomly assigns each second grader to participate in the reading intervention program or not participate in the program. The researcher knows that the standard deviation of the reading comprehension scores among all second graders is σ = 13.35.

Group 1 consists of n₁ = 38 second graders who did not participate in the program. Their mean reading comprehension score is M₁ = 22.8. Group 2 consists of n₂ = 42 second graders who did participate in the program. Their mean reading comprehension score is M₂ = 46.1.

Of the plots that follow, which best represents a plot of these results?

Plot A

Plot B

Plot C

Plot D

The brackets or error bars shown at the top of each bar extend __a____ above and below each of the group means. For group 1, the error bar extends __b____ units above and below the mean for group 1.

Answer choices for a:

one standard deviation

One standard error

Answer choices for b:

2.06

15.7

2.17

13.35

Plot A
Plot B
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group 2
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Plot C
Plot D
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Mean Score
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10

Definition Definition Measure of central tendency that is the average of a given data set. The mean value is evaluated as the quotient of the sum of all observations by the sample size. The mean, in contrast to a median, is affected by extreme values. Very large or very small values can distract the mean from the center of the data. Arithmetic mean: The most common type of mean is the arithmetic mean. It is evaluated using the formula: μ = 1 N ∑ i = 1 N x i Other types of means are the geometric mean, logarithmic mean, and harmonic mean. Geometric mean: The nth root of the product of n observations from a data set is defined as the geometric mean of the set: G = x 1 x 2 ... x n n Logarithmic mean: The difference of the natural logarithms of the two numbers, divided by the difference between the numbers is the logarithmic mean of the two numbers. The logarithmic mean is used particularly in heat transfer and mass transfer. ln x 2 − ln x 1 x 2 − x 1 Harmonic mean: The inverse of the arithmetic mean of the inverses of all the numbers in a data set is the harmonic mean of the data. 1 1 x 1 + 1 x 2 + ...

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