the mean speed of vehicles on a stretch of I-84 is 69/5 mph, with a standard deviation of 4 mph. A random sample of 64 vehicles is selected. Find the probabilty that the mean speed is 70 mph

Asmall business produces and sells balls. the fixed costs are $20 and each ball costs $4.32 to produce. each ball sells for $8.32. write the equations for the total cost, c, and the revenue, r, then use the graphing method to determine how many balls must be sold to break even.