Final answer:
A decreasing level of confidence while holding other quantities constant would lead to a d) wider interval in statistics to estimate a population parameter.
Step-by-step explanation:
A decreasing level of confidence while holding other quantities constant would lead to a wider interval. In statistics, confidence intervals are used to estimate a population parameter, such as the mean. A higher level of confidence indicates a greater level of certainty.
By decreasing the level of confidence, we become less certain about our estimate, which leads to a wider interval. This wider interval allows for a greater range of possible values for the true mean height of Canadian rodeo clowns.