HELP ME PLS ITS EASYYY (hopefully) Mr. Herr pays $9 for 2.5 pounds of chicken at the grocery store. What is the cost per pound?
Explain how you solved this problem and what you got as your answer.
Please don't only give me the answer, actually EXPLAIN.

$3.60 per pound

Step-by-step explanation:

you can set up a proportion:  $ / lbs = $ / lb

let 'x' = cost of 1 pound of chicken:

9 / 2.5 = x / 1

cross-multiply:

2.5x = 9

x = 9/2.5

x = 3.6

The mean run time of the engines is greater than 300 minutes

Step-by-step explanation:

Null hypothesis: The mean run time of the engines is 300 minutes.

Alternate hypothesis: The mean run time of the engines is greater than 300 minutes.

Test statistic (Z) = (sample mean - population mean) ÷ sd/√n

sample mean = 305 minutes

population mean = 300 minutes

sd = 30 minutes

n = 50

Z = (305 - 300) ÷ 30/√50 = 5 ÷ 4.243 = 1.178

The test is a one tailed test. Using a 0.01 significance level, the critical value which is obtained from the standard normal distribution table is 2.326.

Conclusion:

Since the test statistic 1.178 is less than the critical value 2.326, reject the null hypothesis.

There is sufficient evidence to support the claim that the mean run time is more than 300 minutes.