R - 37 = 9 so what dose r = ?

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.

What could explain what happened when the time was equal to 120 minutes

If you answer right ill give brainliest, : )