#1
What is the null hypothesis in statistical hypothesis testing?
The hypothesis that there is no significant difference or relationship
ExplanationNull hypothesis assumes no difference or relationship.
#2
In hypothesis testing, what does p-value represent?
Probability of observing the data if the null hypothesis is true
Explanationp-value indicates the probability of observing data if null hypothesis is true.
#3
What is the Type I error in hypothesis testing?
Rejecting the null hypothesis when it is true
ExplanationType I error is falsely rejecting a true null hypothesis.
#4
Which of the following is NOT a requirement for performing a hypothesis test?
Equal variances in the samples
ExplanationUnequal variances may not be a requirement for hypothesis testing.
#5
Which statistical test is appropriate for comparing the means of two independent groups?
Independent samples t-test
ExplanationIndependent samples t-test compares means of two separate groups.
#6
What is the formula for the test statistic in a one-sample z-test for proportions?
(p̂ - P) / sqrt(p̂ * (1 - p̂) / n)
ExplanationFormula for one-sample z-test statistic for proportions.
#7
What is the purpose of a confidence interval?
To estimate the population parameter
ExplanationConfidence interval estimates population parameter.
#8
In hypothesis testing, what does the power of a test measure?
The probability of correctly rejecting the null hypothesis
ExplanationPower measures the ability to correctly reject null hypothesis.
#9
What is the formula for the test statistic in a one-sample t-test for means?
(x̄ - μ) / (s / sqrt(n))
ExplanationFormula for one-sample t-test statistic for means.
#10
In statistical hypothesis testing, what does a confidence level represent?
The percentage of confidence in the estimation
ExplanationConfidence level represents the certainty of estimation.
#11
What is the critical value used for hypothesis testing typically based on?
Sample size and level of significance
ExplanationCritical value depends on sample size and significance level.
#12
When performing a two-sample t-test, what assumption is made about the variances of the two groups?
They can be equal or unequal
ExplanationVariances in two-sample t-test can be equal or unequal.
#13
Which of the following is true about a one-tailed test compared to a two-tailed test?
A one-tailed test has a smaller rejection region.
ExplanationOne-tailed test has a smaller region for rejection.
#14
What is the correct interpretation of a 95% confidence interval for a population mean?
In 95% of repeated sampling, the calculated interval will contain the true population mean.
Explanation95% confidence interval contains the true population mean in 95% of samples.
#15
Which statistical test is appropriate for comparing the means of more than two independent groups?
ANOVA
ExplanationANOVA compares means of multiple independent groups.
#16
Which of the following is NOT a requirement for performing a two-sample t-test?
The populations have equal variances.
ExplanationTwo-sample t-test doesn't require equal variances.