The sum of the interior angles of a quadrilateral equals. 180 270 360 540

The sum of the interior angles of a quadrilateral equals _360°

C is correct.

Step-by-step explanation:

The sum of the interior angles of a quadrilateral equals

The quadrilateral has four sides and four angles.

First we draw a diagonal of quadrilateral and it makes two triangle.

Sum of angles of triangle is 180° (Angle sum property of triangle)

A quadrilateral form by two triangle

Sum of interior angle of quadrilateral = 180° + 180°

                                                              = 360°

The sum of the interior angles of a quadrilateral equals _360°

We have a general formula sum of interior angles of polygon.

Sum of angles of polygon having n sides = (n-2)180°

For quadrilateral, n = 4

Sum of angles of quadrilateral = (4-2)180°

                                                   = 360°

Option b: The researcher should reject the null hypothesis with either a = 0.05 or a = 0.01.

Step-by-step explanation:

We are given that a researcher administers a treatment to a sample of n = 25 participants and uses a hypothesis test to evaluate the effect of the treatment. The hypothesis test produces a z-score of z = 2.77.

Also, it is assumed that the researcher is using a two-tailed test.

Now, firstly we will find the critical value of z at significance level 0.05 and 0.01.

Our decision rule will be ;

So, at 0.05 significance level z table gives critical value of 1.96.

and at 0.01 significance level z table gives critical value of 2.5758.

As we can clearly see that our z score is more than both the critical values of z at significance level 0.05 and 0.01 so we have sufficient evidence to reject null hypothesis at both significance level.

Hence, the researcher should reject the null hypothesis with either a = 0.05 or a = 0.01.