Use signed numbers to solve. a helicopter descended 1200 feet, rose 800 feet, and then descended 450 feet. what was the net gain or loss in altitude? a. lost 2450 ft b. lost 850 ft c. gained 850 ft d. gained 2450 ft

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?