Tracy had 87 nickels. she used some of her nickels to buy a cookie. tracy later found 19 nickels in her backpack. now tracy has 64 nickels. how many nickels did tracy use to buy the cookie?

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?