A geyser is a hot spring that periodically erupts a mixture of hot water and steam. Old Faithful in Yellowstone National Park is the world's most famous geyser. It is suspected that there is a correlation between the duration of the eruptions and the wait time between eruptions. Using the data file Old Faithful. xlsx (Links to an external site.)Links to an external site., find the linear regression line which uses the duration of an eruption to predict the wait time until the next eruption, and construct a 95% confidence interval for the slope of this line. What is the y-intercept of the equation?