A study gives the following results for a total sample size of 8. 2, 3, 5, 8, 8, 10, 10, 12 The mean of the sample is 7.25.
What is most nearly the standard deviation? [LO:MTH]
a) 2.5
b) 2.9
c) 3.3
d) 3.7

The table above shows approximate conversions from gallons to liters. what is the value of x?

The distribution of the amount of money spent by students for textbooks in a semester is approximately normal in shape with a mean of $235 and a standard deviation of $20. according to the standard deviation rule, how much did almost all (99.7%) of the students spend on textbooks in a semester?

Which of the following parabolas opens up?