Estimate the sum of 13 and 45

Which of the following are independent events? a) knowing that it is going to rain tomorrow, and bringing an umbrella to schoolb) knowing that you have to get up early tomorrow, and going to bed before 9 p.mc) knowing that it is going to rain tomorrow, and going to bed before 9 p.md) knowing that you have a test in school tomorrow, and studying thw night before

Quickly multiply and simplify polynomials (x – 4) (x^2 – 5x – 6)

If the alternate hypothesis of an experiment is “the true mean height of the giraffes is more than 15 feet” what is the null hypothesis?