SAS Training Self-Assessment

Statistics 1: Introduction to ANOVA, Regression, and Logistic Regression

Select the best answer for each question. When you are finished, click Submit Quiz.

  1. For a normal distribution, which of the following statistics is a good measure for the middle of the data?

     a.   mean
     b.   mode
     c.   median
     d.   They are all the same.

  2. Which of the following statements is true about the central limit theorem?

     a.   The central limit theorem states that the sample variance is at most 30 when the sample size is large enough.
     b.   The central limit theorem states that sample variances are approximately equal when sample sizes are equal and large enough.
     c.   The central limit theorem states that the distribution of sample means is approximately normal when the sample size is large enough.
     d.  

    The central limit theorem states that the distribution of sample proportions is approximately equal when the sample size is at least 30.


  3. How do you define the term power?

     a.  
    the probability of rejecting the null hypothesis when it is actually true
     b.   the probability of rejecting the null hypothesis when it is actually false
     c.   the probability of failing to reject the null hypothesis when it is actually false
     d.  
    the probability of failing to reject the null hypothesis when it is actually true

  4. Which of the following lists contains only continuous variables?

     a.   gender, gas mileage, beverage size, income
     b.   age, body temperature, gas mileage, income
     c.   number of children, gender, gas mileage, income
     d.   body temperature, number of children, gender, beverage size

  5. Which of the following statements correctly interprets a 95% confidence interval (15.02, 15.04) for the population mean, if the sample mean is 15.03?

     a.  
    95% of all sample means fall between 15.02 and 15.04.
     b.   95% of all sample confidence intervals will include 15.03.
     c.   You are 95% confident that the true sample mean falls between 15.02 and 15.04
     d.  
    You are 95% confident that the true population mean falls between 15.02 and 15.04.


  6. Which two parameters determine the scale and location of a normal distribution?

     a.  
    the mean (x̄) and the standard deviation (s)
     b.  
    the mean (μ) and the standard deviation (σ)
     c.   the standard deviation (σ) and the variance (σ2)
     d.  
    none of the above.

  7. Which statement below is true regarding the standard error of the mean?

     a.  
    related to the sample size
     b.  
    used to calculate confidence intervals of the mean
     c.  
    both a and b
     d.  
    none of the above.

  8. Which of the following is a valid method for checking the normality of your data?

     a.  
    check if the mean and median are nearly equal
     b.  
    check if the skewness and kurtosis statistics are close to 0
     c.  
    create histograms and other graphical tools to visually assess the data
     d.  
    all of the above

  9. Suppose you have data that is normally distributed with a mean of 0 and a standard deviation of 1. You would expect approximately 95% of the data values to fall between which two numbers?

     a.  

    -.5 and .5
     b.  

    0 and 2
     c.  

    -1 and 1
     d.  

    -2 and 2

  10. Suppose a bank manager is concerned that the percent of loans processed that contain errors has increased above the acceptable amount of 1%. A significance test is conducted to test his concern, and a p-value of .037 is reported at α=0.05 significance level. Which of the following sets of statements is true?

     a.  
    The probability of getting this result, or a more extreme result, given H0 is true, is 0.037. It is lower than the 0.05 significance level. Therefore, there is sufficient evidence to reject H0.
     b.   The probability of getting this result, or a more extreme result, given H0 is true, is 0.037. It is lower than the 0.05 significance level. Therefore, there is not sufficient evidence to reject H0.
     c.  
    The probability of getting this result, or a less extreme result, given H0 is true, is 0.05. It is higher than the 0.037 significance level. Therefore, there is not sufficient evidence to reject H0.
     d.  
    The probability of getting this result, or a less extreme result, given H0 is true, is 0.05. It is higher than the 0.037 significance level. Therefore, there is sufficient evidence to reject H0.