Aweb page design firm has two designs for an online hardware store. to determine which is the more effective design, the firm uses one page when on a mobile platform and a second page when on a desktop. for each visit, the firm records the amount spent by the visitor and the amount of time visiting the site. complete parts (a) through (c) below (a) what is the explanatory variable in this study? is it qualitative or quantitative? o a. the explanatory variable is the amount spent by the visitor. this explanatory variable is quantitative. o b. the explanatory variable is the web page design. the explanatory variable is qualitative. ° c. the explanatory variable is the amount of time visiting the site. this explanatory variable is quantitative o d. the explanatory variable is the age group. this explanatory variable is qualitative. (b) what are the two response variables? for each response variable, state whether it is qualitative or quantitative. select all that apply. □ a- one response variable is the amount spent by the visitor. this response variable is quantitative. b. one response variable is the web page design. this response variable is qualitative. c. one response variable is the age group. this response variable is qualitative d. one response variable is the amount of time visiting the site. this response variable is quantitative. (c) explain how confounding might be an issue with this study. choose the correct answer below d a. since there are two response variables in this study, they may interact, causing the results to be misleading or incorrect. b. since there is only one explanatory variable, and two response variables, the explanatory variable will not affect both response variables equally, resulting in misleading results o c. since the designs are being tested with two different age groups, preferences depending on the age group may affect the response variables for those groups. o d. since the variables are not all quantitative or all qualitative, they may interact, causing the results to be misleading or incorrect.