PLEASE HELP. algebra homework question 3.

Given the following sampling distribution of one mean with a sample size 49, from a normally distributed population,find the population standard deviation, o.79828588912497

Aline has a slope of 1/4 and passes through point (0.4,-1/2). what is the value of the y-intercept?

What is the range of the function? f(x)=-2|x+1|? a. all real numbers. b. all real numbers less than or equal to 0. c. all real numbers less than or equal to 1. d. all real numbers greater than or equal to 1