MS 150 Statistics Spring 2003 • Name: _____________________

CO2 bubbles/minute

Part I: Basic Statistics and Histogram

Last week the SC 120 Biology made measurements of the respiration rate of yeast by counting the rate at which the yeast produced carbon dioxide bubbles. Yeast produces carbon dioxide as a by-product of respiration. The student's data is recorded in the table. Calculate the following statistics for the bubble rate data:

  1. __________ Find the sample size n.
  2. __________ Find the minimum bubble rate.
  3. __________ Find the maximum bubble rate.
  4. __________ Find the range of the bubble rate.
  5. __________ Find the median bubble rate.
  6. __________ Find the mode for the bubble rate.
  7. __________ Find the sample mean bubble rate.
  8. __________ Find the sample standard deviation bubble rate.
  9. __________ Find the sample coefficient of variation CV.
  10. __________ If this data is divided into five bins, what is the width of a single bin?
  11. Determine the frequency and calculate the relative frequency using five bins. Record your results in the table provided.
    Bins (x) Frequency (f) P(x)
    _______ _______ _______
    _______ _______ _______
    _______ _______ _______
    _______ _______ _______
    _______ _______ _______
    Sum: _______ _______
  12. Sketch a relative frequency histogram of the data here or on the back, labeling your horizontal axis and vertical axis as appropriate.
  13. __________ What is the shape of the distribution?
  14. __________ Determine P(x <= 6 bubbles/minute)
  15. __________ Determine P(x > 18 bubbles/minute)

Part II: Linear regression

Celsius/C CO2
19 0.6
28 2.9
29 4.3
34 15.7
39 21.3
  1. __________ Calculate the slope of the best fit line for the temperature versus bubble rate data.
  2. __________ Calculate the y-intercept for the data.
  3. __________ Is the correlation positive, negative, or neutral?
  4. __________ Determine the correlation coefficient
  5. __________ Is the correlation none, low, moderate, high, or perfect?
  6. __________ Determine the coefficient of determination.
  7. __________ What percent in the variation in temperature explains the variation bubble rate?
  8. What would you tell an SC 120 Biology student who asked whether the temperature is a good predictor of the respiration rate for the yeast?
  9. __________ Based on the best fit line and the data, does yeast respiration increase or decrease with increasing temperature?
  10. __________ Based on the equation of the best fit line, what would be the predicted bubble rate at 24C?
  11. __________ Based on the equation of the best fit line, what would be the predicted temperature for a bubble rate of 10 bubbles per minute?
  12. __________ Based on the equation of the best fit line, what would be the predicted bubble rate at 100C?
Statistic or Parameter Symbol Equations Excel
Square root =SQRT(number)
Sample mean xbar.gif (842 bytes) Sx/n =AVERAGE(data)
Sample standard deviation sx =STDEV(data)
Sample Coefficient of Variation CV 100(sx/xbar.gif (842 bytes)) =100*STDEV(data)/AVERAGE(data)
Slope b =SLOPE(y data, x data)
Intercept a =INTERCEPT(y data, x data)
Correlation r =CORREL(y data, x data)
Coefficient of Determination r =(CORREL(y data, x data))^2

Do you use the textbook?
Do you find the textbook to be helpful?
What would be your comments on changing from using the textbook to having the students purchase bound copies of the class notes from the bookstore for next Fall?