The water level at a local pier rises and falls with the tide. Yesterday, the maximum depth of the water at the pier was 8 feet, and the minimum depth was 4 feet. High tide occurred at 12:00 AM and low tide
occurred at 12:20 PM. Which function models the depth, in feet, of the water at the pier yesterday, as a
function of time t in minutes past high tide?

Recall that the owner of a local health food store recently started a new ad campaign to attract more business and wants to know if average daily sales have increased. historically average daily sales were approximately $2,700. the upper bound of the 95% range of likely sample means for this one-sided test is approximately $2,843.44. if the owner took a random sample of forty-five days and found that daily average sales were now $2,984, what can she conclude at the 95% confidence level?