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50 Points!

What is the standard deviation of the following data set rounded to the nearest tenth? 3, 17, 18, 15, 12, 21, 9

Plz answer asap! i will reward brainliest and 12 points for these three questions!take notice: these three questions are completely different! 1) what is the percentage of sugar in the syrup made of 10 kg of water and 4 kg of suugar? 2) what was the original price if after 10% discount it became $450? 3) at first a price was decreased by 12%, then it was disounted again by an additional 5%. what is the percent of the total discount? , and remeber i will award brainliest and 12 points!

If you draw a card with a value of three or less from a standard deck of cards, i will pay you $43. if not, you pay me $11. (aces are considered the highest card in the deck.) step 1 of 2 : find the expected value of the proposition. round your answer to two decimal places. losses must be expressed as negative values.