Need help ASAP please

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.

Which number line represents the solution set for the inequality -1/2x> 24?

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?