1. You randomly survey people in the mall about whether or not they
regularly use text messaging. The results are shown in the tally sheets
below based on the people’s ages.
Link to the tally sheets: http://www.intervisualtechnology.us/data/1/16381/textregular.jpg
a. Make a two-way table that includes the marginal frequencies.
b. Make a two-way table that shows both the joint and marginal relative frequencies. Round to the nearest hundredth, if necessary.
c. What is the probability that someone who is between the ages of 20-29 also texts regularly?
d. What is the probability that someone who is between the ages of 40-49 also texts regularly?
e. Does the data show a relationship between age and texting? Explain.
2. The data below represents the number of hits on your web site over 10 months.
a. Make a scatter plot of ln y versus x. Use the scatter plot to find the equation for the line of best fit.
b. Make a scatter plot of ln y versus ln x. Use the scatter plot to find the equation for the line of best fit.
c. Based on your answers in part a and b, would an exponential model or a power model be better to represent this data? Explain.
d. Use your answers from parts a and b to find an exponential model and a power model to represent this data by hand.
e. Use the regression feature on your calculator to find an exponential model and a power model to represent this data.
f. Use your answer from parts c and d to make the best estimate for the number of hits your web site will have in 12 months.