For a normal distribution curve with a mean of 21 and a standard deviation of 5, which range of the variable defines an area under the curve corresponding to a probability of approximately 68%?
a. from 18.5 to 23.5
b. from 16 to 26
c. from 21 to 31
d. from 11 to 31

Fawn bought a total of 70 cakes for a tea party. she spent $3,025. fawn bought vanilla cakes for $22 each and a fruit filled cake for $55 each. the system of equations below can be used to find the number of vanilla cakes, v, and the number of fruit filled cakes, f, fawn purchased. which system of equations has the same solution as the system below.