In a study of 225 adults, the average heart rate was 72 beats per minute. Assume the population of heart rates is known to be ap
proximately normal, with a standard deviation of 10 beats per minute. What does a margin of error of 1.1 for the 90% confidence interval of the average beats per minute mean?
She worked 2 1/2 hrs yesterday and 4 1/4 hrs today... 2 1/2 + 4 1/4 = 2 + 4 = 6 1/2 + 1/4 = 2/4 + 1/4 = 3/4 so she worked a total of 6 3/4 hrs....or 6.75 hrs
she is paid $ 54
54 / 6.75 = $ 8 per hr <=== what she earned per hr