The list below shows the number of seconds each of 15 dogs took to complete an obstacle course. 52, 51, 57, 63, 56, 50, 57, 59, 43, 59, 52, 58, 57, 45, 51
What is the standard deviation of the numbers listed?
O 5.49
O 15
O 56
O 54

Abox contains 1 plain pencil and 4 pens. a second box contains 5 color pencils and 5 crayons. one item from each box is chosen at random. what is the probability that a plain pencil from the first box and a color pencil from the second box are selected? write your answer as a fraction in simplest form.

The swimming pool is open when the high temperature is higher than 20∘c. lainey tried to swim on monday and thursday (which was 33 days later). the pool was open on monday, but it was closed on thursday. the high temperature was 30 ∘c on monday, but decreased at a constant rate in the next 33 days. write an inequality to determine the rate of temperature decrease in degrees celsius per day, d, from monday to thursday.

Cos^2x+cos^2(120°+x)+cos^2(120°-x)i need this asap. pls me