Revision Sem 3

What is the significance level used for in hypothesis testing?

• Rejecting the null hypothesis

• Accepting the null hypothesis

• Determining the confidence interval

• Calculating the sample size

What is the critical region in hypothesis testing?

• The range of the sample data

• The set of values for which the null hypothesis is rejected

• The set of values for which the null hypothesis is accepted

• The margin of error

How can the width of a confidence interval be reduced?

• Increase the percentage of confidence interval

• Increase the sample size

• Increase the confidence level

• Decrease the sample size

What does the confidence interval indicate?

• The exact population mean

• The range of possible population parameters

• The sample mean

• The standard deviation

What is the standard normal random variable characterized by?

• Mean of 1 and variance of 1

• Mean of 1 and variance of 0

• Mean of 0 and variance of 1

• Mean of 0 and variance of 0

Why can Poisson distribution not be an exact model for Y?

• The mean number of Y is constant

• The mean number of Y is known

• The number of Y is finite and limited

• The number of Y is infinite

What is the null hypothesis in hypothesis testing?

• A statement about the population parameter

• A statement about the sample parameter

• A statement about the confidence level

• A statement about the standard deviation

What is the critical value used for in hypothesis testing?

• Calculating the confidence interval

• Estimating the population mean

• Determining the sample size

• Comparing to the test statistic to reject the null hypothesis

What does 'at the 5% significance level' mean?

• The probability of a type one error

• The probability of rejecting the null hypothesis

• The probability of a type two error

• The probability of accepting the null hypothesis

Why is the median considered the best measure of central tendency?

• Because the data is positively/negatively skewed

• Because the data is skewed

• Because the data is symmetrical

• Because the data is random