Math problem - Speech or Presentation Example

4. Suppose you administered an anxiety test to a large sample of people and obtained normally distributed scores with a mean of 45 and standard deviation of 4. Do not use web-calculator to answer the following questions. Instead, you need to use the Z distribution table in Appendix A in Jackson’s book. a. If Andrew scored 45 on this test. What is his Z score? Z= (µ-x)/s = (45-45)/4=0b. If Anna scored 30 on this test. What is her Z score? Z= (µ-x)/s = (30-45)/4 = 3.75c. If Bill’s Z score was 1.

5, what is his real score on this test? µ = (Z*s)/x = (1.5*4)/45=0.1333d. There are 200 students in a sample. How many of these students will have scores that fall under the score of 41? The z-score for 41= (41-45)/4=-1 Decimal For a s.d of -1 from the table= .159 =0.159*200=31.8= 31 students5. The table below shows Psychology exam scores, Statistics Exam scores, and IQ scores for a random sample of students. What can you observe in the relationship between IQ and psychology, psychology and statistics, and IQ and statistics?

Using a web-calculator, obtain the Pearson’s r and coefficient of determination for the following relationships. a. Between the IQ and psychology scores r= 0.5923Online calculator: http://www.meta-numerics.net/Samples/BivariateSampleCalculator.aspxR2 = 0.3508 Online calculator: http://easycalculation.com/statistics/r-squared.php b. Between the IQ and statistics scoresr= 0.7366Online calculator: http://www.meta-numerics.net/Samples/BivariateSampleCalculator.aspxR2= 0.0318Online calculator: http://easycalculation.

com/statistics/r-squared.php c. Between the psychology scores and statistics scores. r=0.7104Online calculator: http://www.meta-numerics.net/Samples/BivariateSampleCalculator.aspxR2= 0.3134Online calculator: http://easycalculation.com/statistics/r-squared.php 6. In a study on caffeine and stress, college students indicated how many cups of coffee they drink per day and their current stress level on a scale of 1 to 10. The table shows the survey results. Using a web-calculator, obtain the appropriate correlation coefficients.

Number of cups of coffeeStress level 35234369541271035r= 0.85190R2= 0.7257Online calculator: http://easycalculation.com/statistics/r-squared.php ReferenceSoong, T.-T. (2004). Fundamentals of probability and statistics for engineers. Hoboken, NJ [u.a.: Wiley.