Astatistics professor asked students in a class their ages. on the basis of this information, the professor states that the average age of all the students in the university is 21 years.
this is an example of a:

a. census
b. descriptive statistics
c. an experiment
d. statistical inference

Option D. statistical inference        

Step-by-step explanation:

We are given the following situation in the question:

"A statistics professor asked students in a class their ages. On the basis of this information, the professor states that the average age of all the students in the university is 21 years."

This is a n example of statistical Inference.

b. an equilateral triangle inscribed in a circle

step-by-step explanation:

we are given the figure of two circles having a triangle inside.

now, we know that,

"when a figure is lying inside an another figure, then the outside figure is known as circumscribed figure and the figure lying inside is referred to as the inscribed figure".

as we see that, the circles are containing the triangle completely.

thus, the circles are the circumscribed figures and the triangle is the inscribed figure.

hence, we get, 'an equilateral triangle is inscribed in a circle'.

20

step-by-step explanation: