Last year, the standard deviation of the ages of the students at ua was 1.8 years. recently, a sample of 31 students had a standard deviation of 2.1 years. we are interested in testing to see if there has been a significant change in the standard deviation of the ages of the students at ua. the null hypothesis is

Step-by-step explanation:

Let represents the standard deviation .

Given : Last year, the standard deviation of the ages of the students at UA was 1.8 years.

The researcher are interested in testing to see if there has been a significant change in the standard deviation of the ages of the students at UA.

We know that the null hypothesis always contains the equal signs, then the null and alternative hypothesis is given by :-

there are many solutions.

step-by-step explanation:

step 1: simplify both sides of the equation.

4x+6=4x^2+10x−4

step 2: subtract 4x^2+10x-4 from both sides.

4x+6−(4x^2+10x−4)=4x^2+10x−4−(4x^2+10x−4)

−4x^2−6x+10=0

step 3: factor left side of equation.

−2(2x+5)(x−1)=0

step 4: set factors equal to 0.

x=-5/2 or x=1

the figures below are made out of circles, semicircles, quarter … find the area and the perimeter of each figure and give your answers as a completely simplified exact value in terms of π (no approximations). remember that we'll also have to cut whatever areas we get in half, since we're only dealing im pretty sure that is the right answer

step-by-step explanation: