Na study of 250 adults, the mean heart rate was 70 beats per minute. assume the population of heart rates is known to be approximately normal with a standard deviation of 12 beats per minute. what is the 99% confidence interval for the mean beats per minute?

Suppose there is a simple index of three stocks, stock abc, stock xyz, and stock qrs. stock abc opens on day 1 with 4000 shares at $3.15 per share. stock xyz opens on day 1 with 5000 shares at $4.30 per share. stock qrs opens on day 1 with 6000 shares at $4.60 per share. the price of stock abc on day 8 begins at $3.50. the price of stock xyz on day 8 begins at $3.90. stock qrs opens on day 8 with a price of $4.50 per share. assume that each stock has the same number of shares that it opened with on day 1. what is the rate of change of this simple index over 1 week?

Four congruent circular holes with a diameter of 2 in. were punches out of a piece of paper. what is the area of the paper that is left ? use 3.14 for pi

Me! i will mark brainliest! i don't get polynomials and all that other stuff. so this question is really hard. multiply and simplify.(x - 4) (x^2 – 5x – 6)show your