Fifteen more than half a number is equal to 9

The contents of 3838 cans of coke have a mean of x¯¯¯=12.15x¯=12.15. assume the contents of cans of coke have a normal distribution with standard deviation of σ=0.12.σ=0.12. find the value of the test statistic zz for the claim that the population mean is μ=12.μ=12.

Each cookie sells for $0.50 sam spent $90 on baking supplies and each cookie cost $0.25 to make how many cookies does sam need to sell before making a profit formula: sales> cost

Is the power produced directly proportional to the wind speed, give reasons for your answer?