Hi im tryna turn in a missing assignment and i need help-

In a class, there are 12 girls. if the ratio of boys to girls is 5: 4 how many boys are there in the class

Which expression do you get when you eliminate the negative exponents of 4a^2 b^216a^-3 b

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?