Inferential Statistics: Hypothesis Testing and Confidence Intervals for Nursing Students

Question 1

To test the claim that the mean weight of newborn babies is 7.5 pounds, which of the following is the appropriate null hypothesis?

Accepted Answer

H0: μ = 7.5

Answer

H0: μ > 7.5

Answer

H0: μ < 7.5

Answer

H0: μ ≠ 7.5

Question 2

In a 95% confidence interval, what is the probability that the true population parameter falls outside the interval?

Accepted Answer

0.05

Answer

0.95

Answer

0.25

Answer

0.75

Question 3

Which condition is NOT necessary for the Central Limit Theorem to be applicable?

Accepted Answer

Population variance is known

Answer

Sample size is large (n ≥ 30)

Answer

Population distribution is normal

Answer

Sampling is random

Question 4

Which interpretation of a confidence interval is correct?

Accepted Answer

We are 95% confident that the true population parameter lies within the interval

Answer

There is a 95% chance that the true population parameter lies within the interval

Answer

The true population parameter is 95% likely to be within the interval

Answer

We can be 95% sure that the true population parameter is equal to the midpoint of the interval

Question 5

A researcher obtains a sample of 50 data points with a sample mean of 100. The population standard deviation is known to be 15. What is the standard error of the mean?

Accepted Answer

2.12

Answer

3.00

Answer

4.24

Answer

6.32

Question 6

Which of the following is the appropriate alternative hypothesis for a left-tailed hypothesis test?

Accepted Answer

H1: μ < 7.5

Answer

H1: μ > 7.5

Answer

H1: μ = 7.5

Answer

H1: μ ≠ 7.5

Question 7

Which method is most effective for determining if data is normally distributed?

Accepted Answer

Creating a histogram

Answer

Calculating the mean and standard deviation

Answer

Plotting the data on a scatterplot

Answer

Using a chi-square test

Question 8

Which step is NOT involved in hypothesis testing?

Accepted Answer

Conduct an experiment

Answer

State the hypotheses

Answer

Collect data

Answer

Make a conclusion

Question 9

What is the primary purpose of constructing a confidence interval?

Accepted Answer

To estimate a population parameter

Answer

To test a hypothesis

Answer

To determine the probability of an outcome

Answer

To compare two or more groups

Question 10

In a two-sample t-test, what is the null hypothesis?

Accepted Answer

The means of the two populations are equal

Answer

The means of the two populations are not equal

Answer

The difference between the two means is zero

Answer

The difference between the two means is not zero

Question 11

What is the term for the probability of rejecting the null hypothesis when it is actually true?

Accepted Answer

Type I error

Answer

Alpha

Answer

Beta

Answer

Type II error

Question 12

Which of the following is NOT a limitation of using inferential statistics?

Accepted Answer

Can make inferences about the entire population

Answer

Assumptions must be met

Answer

Results may not be reliable

Answer

Sample may not be representative

Question 13

In hypothesis testing, the null hypothesis proposes that:

Accepted Answer

There is no significant difference or effect.

Answer

There is a significant difference or effect.

Answer

The results are inconclusive.

Answer

The sample is representative of the population.

Question 14

When constructing a confidence interval for a population mean, a 95% confidence level indicates that:

Accepted Answer

There is a 95% probability that the population mean falls within the interval.

Answer

There is a 95% probability that the sample mean falls within the interval.

Answer

The sample mean is 95% likely to be the true population mean.

Answer

The probability of the population mean falling outside the interval is 5%.

Question 15

To calculate the p-value in a hypothesis test, we assume that:

Accepted Answer

The null hypothesis is true.

Answer

The alternative hypothesis is true.

Answer

The sample is representative of the population.

Answer

The data is normally distributed.

Question 16

When using a t-test, which of the following assumptions is crucial?

Accepted Answer

The data is normally distributed.

Answer

The population standard deviation is known.

Answer

The sample size is large (n > 30).

Answer

The sample is random.

Question 17

To determine the strength and direction of a relationship between two continuous variables, which statistical test is appropriate?

Accepted Answer

Pearson correlation coefficient

Answer

Spearman rank correlation coefficient

Answer

Kendall rank correlation coefficient

Answer

ANOVA

Question 18

Which research design allows for the strongest control over variables and cause-and-effect relationships?

Accepted Answer

Experimental design

Answer

Observational study

Answer

Case study

Answer

Meta-analysis

Question 19

Which of the following is the formula for a confidence interval for a proportion?

Accepted Answer

p ± z * sqrt((p(1-p))/n)

Answer

p ± t * sqrt((p(1-p))/n)

Answer

z ± p * sqrt((p(1-p))/n)

Answer

t ± p * sqrt((p(1-p))/n)

Question 20

In hypothesis testing, what is the null hypothesis?

Accepted Answer

The hypothesis that is being assumed to be true.

Answer

The hypothesis that is being tested.

Answer

The hypothesis that is being rejected.

Answer

The hypothesis that is being proven.

Question 21

What is the critical value in hypothesis testing?

Accepted Answer

The value that divides the rejection region from the non-rejection region.

Answer

The value of the test statistic that is compared to the critical value.

Answer

The value of the p-value that is compared to the critical value.

Answer

The value of the sample mean that is compared to the critical value.

Question 22

What is the Type I error rate in hypothesis testing?

Accepted Answer

The probability of rejecting the null hypothesis when it is true.

Answer

The probability of failing to reject the null hypothesis when it is false.

Answer

The probability of making a correct decision.

Answer

The probability of making an incorrect decision.

Question 23

What is the Type II error rate in hypothesis testing?

Accepted Answer

The probability of failing to reject the null hypothesis when it is true.

Answer

The probability of rejecting the null hypothesis when it is false.

Answer

The probability of making a correct decision.

Answer

The probability of making an incorrect decision.

Question 24

What is a one-tailed hypothesis test?

Accepted Answer

A hypothesis test where the alternative hypothesis is one-sided.

Answer

A hypothesis test where the alternative hypothesis is two-sided.

Answer

A hypothesis test where the null hypothesis is one-sided.

Answer

A hypothesis test where the null hypothesis is two-sided.

Question 25

What is a two-tailed hypothesis test?

Accepted Answer

A hypothesis test where the alternative hypothesis is two-sided.

Answer

A hypothesis test where the alternative hypothesis is one-sided.

Answer

A hypothesis test where the null hypothesis is one-sided.

Answer

A hypothesis test where the null hypothesis is two-sided.

Question 26

A confidence interval is constructed with a 95% confidence level. What does this mean?

Accepted Answer

There is a 95% probability that the true population parameter is contained within the interval.

Answer

The sample mean is 95% likely to be within the interval.

Answer

95% of the data points will fall within the interval.

Answer

The researcher is 95% confident that the interval is correct.

Question 27

Which of the following is the null hypothesis in a hypothesis test?

Accepted Answer

The sample mean is equal to the population mean.

Answer

The alternative hypothesis is true.

Answer

The population mean is not equal to the sample mean.

Answer

The sample proportion is equal to the population proportion.

Question 28

In a hypothesis test, the significance level (α) is defined as the probability of:

Accepted Answer

Rejecting the null hypothesis when it is true (Type I error).

Answer

Accepting the null hypothesis when it is false (Type II error).

Answer

Making a Type I error.

Answer

Making a Type II error.

Question 29

Which of the following is a Type I error in hypothesis testing?

Accepted Answer

Rejecting the null hypothesis when it is true.

Answer

Accepting the null hypothesis when it is false.

Answer

Failing to reject the null hypothesis when it is false.

Answer

Rejecting the null hypothesis correctly.

Question 30

The p-value in hypothesis testing is calculated by finding the probability of:

Accepted Answer

Getting a test statistic as extreme as or more extreme than the observed test statistic, assuming the null hypothesis is true.

Answer

Getting a sample mean as large as or larger than the observed sample mean, assuming the null hypothesis is true.

Answer

Accepting the null hypothesis when it is false.

Answer

Making a Type II error.

Question 31

The confidence level of a confidence interval is:

Accepted Answer

The probability that the true population parameter is contained within the interval.

Answer

The probability that the sample mean is contained within the interval.

Answer

The probability that the null hypothesis is true.

Answer

The probability that the p-value is less than 0.05.

Question 32

Which of the following is NOT an assumption of a one-way ANOVA?

Accepted Answer

The sample sizes are different

Answer

The populations are normally distributed

Answer

The samples are independent

Answer

The variances of the populations are equal

Question 33

In regression analysis, the slope of the regression line represents the:

Accepted Answer

change in the dependent variable for each unit change in the independent variable

Answer

correlation coefficient between the dependent and independent variables

Answer

variance of the dependent variable

Answer

mean of the dependent variable

Question 34

In inferential statistics, which approach to data handling is considered the most ethical?

Accepted Answer

Disclosing any data manipulation or exclusion for transparency

Answer

Manipulating data to obtain a specific statistical outcome

Answer

Prioritizing statistically significant results, regardless of their accuracy

Answer

Excluding data that contradicts the desired conclusion

Question 35

The null hypothesis is a statement that:

Accepted Answer

there is no difference between the means of the two populations

Answer

the variance of population A is equal to the variance of population B

Answer

the mean of population A is greater than the mean of population B

Question 36

Which of the following is a type of statistical error that occurs when we reject the null hypothesis when it is actually true?

Accepted Answer

Type I error

Answer

Measurement error

Answer

Sampling error

Answer

Rounding error

Question 37

The sample mean is a:

Accepted Answer

point estimate for the population mean

Answer

sample range

Answer

sample mode

Answer

sample median

Question 38

Which of the following is a method for selecting a random sample where each member of the population has an equal chance of being selected?

Accepted Answer

Simple random sampling

Answer

Quota sampling

Answer

Convenience sampling

Question 39

The primary purpose of a t-test is to:

Accepted Answer

Compare the means of two independent samples.

Answer

Estimate the population proportion.

Answer

Analyze the distribution of a single sample.

Question 40

The assumption of normality in inferential statistics implies that:

Accepted Answer

The data in the population from which the sample is drawn follows a normal distribution.

Answer

The data in the sample itself must be normally distributed.

Answer

The sampling distribution of the sample mean is always normal.

Question 41

Which of the following is NOT a type of inferential statistical method?

Accepted Answer

Descriptive statistics

Answer

Hypothesis testing

Answer

Regression analysis

Question 42

In hypothesis testing, the null hypothesis (H0) serves to:

Accepted Answer

Assume no significant difference or effect.

Answer

Determine the significance level.

Answer

Establish the alternative hypothesis.

Question 43

When conducting a hypothesis test, which type of error occurs if we reject a true null hypothesis?

Accepted Answer

Type I error

Answer

Measurement error

Answer

Type II error

Answer

Sampling error

Question 44

A 95% confidence interval provides an estimate of a population parameter with a confidence level of:

Accepted Answer

95%

Answer

90%

Answer

5%

Answer

100%

Question 45

In a hypothesis testing procedure, the initial step involves:

Accepted Answer

Stating the null hypothesis (H0) and alternative hypothesis (Ha).

Answer

Determining the p-value

Answer

Calculating the test statistic

Question 46

A research study that randomly assigns participants to either an experimental group (receiving a new treatment) or a control group (receiving a standard treatment or placebo) is known as a:

Accepted Answer

Randomized controlled trial (RCT)

Answer

Cohort study

Answer

Observational study

Answer

Case-control study

Question 47

Which measure provides the most comprehensive description of the spread of a distribution?

Accepted Answer

Standard deviation

Answer

Variance

Answer

Range

Answer

Mean absolute deviation

Question 48

According to the central limit theorem, the distribution of sample means approaches which type of distribution as the sample size increases?

Accepted Answer

Normal

Answer

Uniform

Answer

Poisson

Answer

Binomial

Question 49

A researcher aims to determine the effectiveness of a new medication in lowering blood pressure. They randomly select a group of patients with high blood pressure and administer the medication. After a specific period, they measure the patients' blood pressure again. Which type of hypothesis test is most suitable for this scenario?

Accepted Answer

Paired t-test

Answer

One-sample t-test

Answer

Two-sample t-test

Answer

Chi-square test

Question 50

A researcher plans to test the hypothesis that the average age of nurses in a particular hospital is exactly 45 years. They randomly sample the ages of 50 nurses. What is the null hypothesis for this test?

Accepted Answer

The mean age of nurses in the hospital is 45 years.

Answer

The mean age of nurses in the hospital is not 45 years.

Answer

The mean age of nurses in the hospital is greater than 45 years.

Question 51

A 95% confidence interval for the proportion of patients experiencing a side effect from a new drug is (0.10, 0.15). Which interpretation is correct?

Accepted Answer

We are 95% confident that the true proportion of patients experiencing side effects lies between 10% and 15%.

Answer

95% of patients will experience side effects between 10% and 15%.

Question 52

A study aims to investigate the effectiveness of a new exercise program for weight loss. Participants are randomly assigned to either the exercise program group or a control group. Which type of hypothesis test is most appropriate to compare the weight loss between the two groups?

Accepted Answer

Two-sample t-test

Answer

Chi-square test

Answer

One-sample t-test

Answer

Paired t-test

Question 53

A researcher investigates the relationship between smoking and lung cancer. They gather data on the smoking habits and lung cancer status of a significant sample of individuals. Which statistical test is most appropriate for analyzing this data?

Accepted Answer

Chi-square test

Answer

Two-sample t-test

Answer

One-sample t-test

Question 54

A 99% confidence interval for the mean blood pressure of a population is (120 mmHg, 130 mmHg). What is the confidence level associated with this interval?

Accepted Answer

99%

Answer

95%

Answer

90%

Answer

1%

Question 55

A researcher aims to determine if there is a significant difference in the mean weight of infants born to mothers who smoke and those born to mothers who do not smoke. They collect data on the weights of infants born to 100 mothers who smoke and 100 mothers who do not smoke. Which type of hypothesis test is most appropriate for this scenario?

Accepted Answer

Two-sample t-test

Answer

Chi-square test

Answer

One-sample t-test

Answer

Paired t-test

Question 56

A 90% confidence interval for the proportion of patients recovering from a particular illness is (0.75, 0.85). Which interpretation is most accurate?

Accepted Answer

We are 90% confident that the true proportion of patients recovering from the illness falls between 75% and 85%.

Answer

90% of patients will recover from the illness.

Question 57

A researcher conducts a study to determine the relationship between the number of hours of sleep a person gets and their level of stress. Which statistical test is most appropriate for analyzing this data?

Accepted Answer

Correlation analysis

Answer

Two-sample t-test

Answer

Chi-square test

Answer

One-sample t-test