Answered: One method of grading tests that uses a…

Glencoe Algebra 1, Student Edition, 9780079039897, 0079039898, 2018

18th Edition

ISBN:9780079039897

Author:Carter

Publisher:Carter

Chapter10: Statistics

Section10.3: Measures Of Spread

Problem 26PFA

See similar textbooks

Related questions

Question

One method of grading tests that uses a normal curve gives students letter grades depending on the standard‐deviation interval above or below the mean that contains their score: a grade of

F for below −2 standard deviations
D for −2 to −1 standard deviation
C for −1 to +1 standard deviation
B for +1 to +2 standard deviation
A for above +2 standard deviations

In the following, use this grading system and the fact that on a test given to 50 students the mean score was 76 and the standard deviation was 4.

a. How many students received a B?

students

b. How many students received a grade below a C?

students

c. How many students received a grade above an F?

students

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 + ...

Expert Solution