Answered: Lecturers at a university intend to see…

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

See similar textbooks

Related questions

Question

Lecturers at a university intend to see the effect of stress relief strategies such as deep breathing and relaxation techniques to the student performance in the final exam. For this reason, they assigned students of the same year in two different cohorts. More precisely, students in Cohort 1 did not do any relaxation techniques before the exam, while students in Cohort 2 performed a full range of the relaxation techniques approved by the British Psychological Society. The average mark of a random sample of 17 students from Cohort 1 was 61, with a standard deviation of 17, while the average mark of a random sample of 11 students from Cohort 2 was 67 with a standard deviation of 19.

a) Calculate a 95% confidence interval for the difference in average marks in the
exam for the two cohorts of students. Explain the meaning of the 95% confidence interval that you have calculated.

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