,
, Portage Learning CHEM 103 General
Chemistry I Module 2 Exam | 2025
Updated Edition with 100% Verified
Answers
Question 1
A researcher wants to see if the average scores of two independent training classes
differ. Class 1 (\(n_1 = 15\)) has a mean of \(82.4\) and a standard deviation of \(4.5\).
Class 2 (\(n_2 = 15\)) has a mean of \(78.2\) and a standard deviation of \(5.1\).
Assuming equal variances, what is the degrees of freedom (\(df\)) for a two-sample
independent \(t\)-test?
A) 14
B) 28
C) 29
D) 30
Answer: B
Rationale: For a two-sample independent t-test assuming equal variances, the formula
for the degrees of freedom is \(df = n_1 + n_2 - 2\). Plunging in the given sample sizes:
\(df = 15 + 15 - 2 = 28\).
Question 2
Which of the following describes a Type I error in hypothesis testing?
A) Rejecting the null hypothesis when it is true
B) Failing to reject the null hypothesis when it is false
, Portage Learning CHEM 103 General
Chemistry I Module 2 Exam | 2025
Updated Edition with 100% Verified
Answers
Question 1
A researcher wants to see if the average scores of two independent training classes
differ. Class 1 (\(n_1 = 15\)) has a mean of \(82.4\) and a standard deviation of \(4.5\).
Class 2 (\(n_2 = 15\)) has a mean of \(78.2\) and a standard deviation of \(5.1\).
Assuming equal variances, what is the degrees of freedom (\(df\)) for a two-sample
independent \(t\)-test?
A) 14
B) 28
C) 29
D) 30
Answer: B
Rationale: For a two-sample independent t-test assuming equal variances, the formula
for the degrees of freedom is \(df = n_1 + n_2 - 2\). Plunging in the given sample sizes:
\(df = 15 + 15 - 2 = 28\).
Question 2
Which of the following describes a Type I error in hypothesis testing?
A) Rejecting the null hypothesis when it is true
B) Failing to reject the null hypothesis when it is false
