What is the standard deviation of the points 1300,1100,288,225,1150,850,250,200,750,175,134,521,507,173,134,505,461,169,134
Go to this link and they have a calculator that does what you want. You can play with it:
https://www.easycalculation.com/statistics/standard-deviation.php
If you need to do it "by hand", follow the instructions in your text book.
If you need help with those instructions, post back and we will help you.
If you can use an on-line calculator, I suggest: https://www.easycalculation.com/statistics/standard-deviation.php
Good luck!