STATISTICS PRACTICE QUIZ 3
Question 1
A telecommunications company asserts that, according to a study they conducted, patients who have access to more cable channels during recovery from surgery are discharged sooner than those who receive only basic cable in their hospital rooms. Which of the following demonstrates clinical significance of the study?
Patients with more cable channels were discharged an average of one-half day sooner than those with fewer channels
The study used a sample size of 12
Patients with fewer cable channels requested additional nursing support an average of 3 times more during their recovery.
Patients with more cable channels tended to prefer nature and arts channels over history or news and current affairs channels
Question 2
After completing the power analysis, the researchers determine they need a sample size of 400 to have adequate power in their study. After enrolling subjects, they have a lower response rate than anticipated and they only enroll 320. Inadequate enrollment may increase the risk of:
A type II error
Systematic bias
A type I error
Statistical significance
Question 3
Researchers study the relationship between interpersonal violence and health in college age women. The researchers examined the average score on a psychological distress scale and compared the score for abused versus non-abused women. If the researchers report a statistically significant difference and are incorrect about this conclusion what type of error could it be?
A type I error
A type II error
A clinical error
An error of omission
Question 4
Researchers studied the relationship between Vitamin B12 consumption and hair growth and report a p value of 0.56. The study was a pilot study with an alpha of 0.10. You know this means:
There is no statistically significant relationship between Vitamin B12 consumption and hair growth.
Vitamin B12 consumption is association with a 56% increase in hair growth.
The sample size was too small and a type I error was made
There is a statistically significant relationship between Vitamin B12 consumption and hair growth.
Question 5
Researchers study the relationship between interpersonal violence and health in college age women. They selected an alpha of 0.05. The researchers examined the average score on a psychological distress scale and compared the score for abused versus non-abused women. A p value of 0.016 is reported. Based on this information, you know:
There is a statistically significant difference in the average psychological distress score
This is a clinically significant result
There is no significant difference in the average psychological distress score.
In this study women who were abused were statistically more likely to report psychological distress.
Question 6
A study reports that administering vancomycin incorrectly is associated with red man syndrome. You know this means:
The p value is less than alpha
A type I error was made in administering the medication
The p value was larger than the alpha
The null hypothesis was accepted
Question 7
The probability of rejecting the null hypothesis given that it is true describes the:
Alpha level
Sample size
Power
Effect size
Question 8
What does a Z-score of 2.5 indicate?
The observation is 2.5 standard deviations above the mean.
The p-value is closer to 0 than 1
The test results do not conform to a normal distribution.
The alpha level is 0.025
Question 9
How is the actual effect size in a population usually determined?
It must be estimated based on the best literature available.
Multiply the projected effect size by the standard deviation in the control group
Divide the difference between the mean in the experimental group and the mean in the control group by the standard deviation of the experimental group
It is estimated based on the anticipated effect size relative to power.
Question 101 pts
What is the purpose of hypothesis testing?
It determines whether a hypothesis is true
It helps the researcher to develop a null hypothesis
It helps rule out an alternative hypothesis
It determines whether a hypothesis is clinically significant
Question 11
You know the following is true when conducting a hypothesis test
You should determine your significance level or alpha before conducting your statistical test.
Your significance level is higher when your p value is higher.
Your decision is an error if the p value is greater than alpha
When you conduct your statistical analysis, you should adjust your significance level to ensure you achieve statistical significance.
Question 12
A study reports that synthetic marijuana use is associated with altered mental status and tachycardia. You know this means:
There was adequate power to detect a difference
There was an inadequate sample size
A type I error occurred
A type II error occurred
Question 131 pts
Why would a researcher choose a large sample size?
The anticipated effect size is small
The beta is large
The anticipated budget is large
The alpha is small
Question 141 pts
The researcher examines the relationship between hours of sleep and average test scores and reports an r=0.56, p=0.02. You know this means:
All of the answers are correct
There is a statistically significant correlation between sleep and test scores
There is a strong positive relationship between the variables
As hours of sleep increase average test scores do as well
Question 15
A study examines the relationship between total years of educational preparation and total score on a cultural competency exam among a group of 987 randomly selected nurses at your hospital. What test would be appropriate to determine if there is an association?
Pearson’s correlation
Independent t test
Dependent t test
ANOVA
STATISTICS PRACTICE QUIZ 4
Question 1
Inferential statistics involves a process of applying probabilities to:
Variables
Percentiles
Outcomes
Relative frequencies
Question 2
A researcher wants to examine the relationship between age in years and the engagement score (0-100) for 700 nurses enrolled in an online degree program. What test would you recommend she utilize?
Pearson’s Correlation Coefficient
T test for independent groups
Logistical regression
ANOVA
Question 3
You have five groups using different exercise techniques and you want to compare the average number of pounds lost. What statistical test would be appropriate?
ANOVA
T test
Pearson’s Correlation Coeffficient
Chi-square
Question 4
Which of the following assumptions is most important when using ANOVA?
The dependent variable must be at the interval or ratio level
Samples must be dependent
The sample must have normal distribution
There must be homogeneity of variance
Question 5
- A researcher wants to compare the mean engagement score for nurses enrolled in 3 different online degree programs (DNP/MSN/ BSN). What test would you recommend he/she utilize?
ANOVA
T test for independent groups
Logistic regression
Pearson’s Correlation Coefficient
Question 61 pts
You are trying to determine if there is a significant difference in the mean Glasgow coma scale score for patients who are seen with a head injury during the day, evening and night shifts in your emergency room. Your ANOVA results have an F value of 22.33 and a p value of <0.01. You know this means:
There is a significant difference in the mean Glasgow coma scale score for patients seen with a head injury on the three different shifts.
There is NOT significant difference in the mean Glasgow coma scale score for patients seen with a head injury on the three different shifts
A type I error was made.
A Type II error was made
Question 7
You are trying to determine if there is a significant difference in the mean age between patients who have developed a nosocomial infection in your hospital (N=312) and those who have not (N=4,673). What would be an appropriate test to use?
T test for independent groups
T test for dependent groups
Chi-square
Pearsons’s Correlation Coefficient
Question 8
You have measured the performance of 10 participants in a memory test before and after they underwent a new computerized teaching method to improve memory. In order to determine if the computer training improved their memory performance, which type of test can you use?
Dependent t test
Independent t test
Levene’s test
Probability test
Question 9
A researcher wishes to determine if there is a difference in the average flexibility test score for female athletes and the average flexibility test score for their best friends. An appropriate test to utilize would be:
T test for dependent groups
T test for independent groups
Chi-square
ANOVA
Question 101 pts
For which of the following variables is a Student t test appropriate?
Temperature
City of residence
Hair color
Grade of severity (1-5)
Question 111 pts
A study with 890 subjects examines shift worked (day/night) and back injuries (yes/no). An appropriate test to use would be:
Chi-square
Independent t test
ANOVA
T test for dependent groups
Question 121 pts
A study examines the relationship between being a registered nurse (yes/no) and passing a cultural competency exam (yes/no) among a group of 987 randomly selected employees at your hospital. What test would be appropriate to determine if there is an association?
Chi-square
Independent t test
Pearson’s correlation
McNemar’s test
