This recipe makes 2 portions of fajitas. Carly has 700 g of chicken, 950 g of peppers, 100 g of onion, 35 g of spice mix
and 20 tortillas.
How much more of each ingredient will she need to make 8 portions by
following this recipe?
Recipe: Serves 2
200 g chicken
250 g peppers
30 g onion
10 g spice mix
4 tortillas

the weight of the object inside the box!

irst, find the z score of a score of 80. this is given by the formula z = (x-u)/o, where x is the score, u is the mean, and o is the standard deviation. this gives

z = (80-78)/12 = 1/6 = .1667

now, find what percentile a z score of 1/6 correlates to in the normal distribution.

a z score of 1/6 = .1667 is equivalent to the 56.36th percentile of the distribution. so the probability a score is over this is 1-.5636 = .4364

the mean of a sample mean is equal to the original mean. however, the standard deviation of a sample mean is equal to the original standard deviation divided by the square root of n (sample size). so the new standard deviation is 12/sqrt(16) = 3.

the new z score is 80-78/3 = 2/3 = .667. this is equivalent to the 74.86th percentile. so the probability that the mean will be greater than this score is 1-.7486 = .2514.