4. To determine if a triangle is a right triangle, given that you know the length of its sides, you have to check if its lengths follow the Pythagorean theorem.
This theorem states that the square of the hypothenuse (c) is equal to the sum of the squares of the legs of the triangle (a and b), following the expression:

The triangle is:
We have to check that a²+ b² is equal to c².
The square of the hypothenuse is:

The sum of the squares of the legs of the triangle is:

As you can see, the sum of the squares of the legs of the triangle is 100, which is the same as the square of the hypothenuse. The triangle follows the Pythagorean theorem and can be considered a right triangle.
C causw it is used to be a difrent cuase it just is
Answer:
D.No, because some models of cell phones will have a larger market share than others. Measures from different models should be weighted according to their size in the population.
Step-by-step explanation:
(a) Range is the difference between the smallest and largest observation.
Here Smallest observation = 0.63
and Largest observation = 1.48
⇒ Range = 0.85
(b) Standard Deviation is calculate by,

where,
is mean of the observation.
Here, Mean = 0.988
⇒ Standard Deviation = 0.313
(c) Variance is the square of Standard deviation.
Thus, Variance = (Standard Deviation)² = 0.098
(d) Here last option(D) is true i.e. No, because some models of cell phones will have a larger market share than others. Measures from different models should be weighted according to their size in the population.
I believe 10% because 390 and 39 are exactly the same numbers almost