Jack earns 100$ on the first day, 60$ on the second day, 150$ on the third day, 80$ on the fourth day and 90$ on the fifth day. what was his average earnings? (i think we need to add the money he earns and then divide it by 5. am i right? )

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?