2/3 - 1/6 finding the common denominator show me how to do it

Identify a1 and r for the geometric sequence an= -256(-1/4) n-1

Astandard american eskimo dog has a mean weight of 30 pounds with a standard deviation of 2 pounds. assuming the weights of standard eskimo dogs are normally distributed, what range of weights would 99.7% of the dogs have? approximately 26–34 pounds approximately 24–36 pounds approximately 28–32 pounds approximately 29–31 pounds

In a graph with several intervals o data how does a constant interval appear? what type of scenario produces a constant interval?