B

9000153301

Level: 
B
A student performed repeated measurements of a length (in meters) and evaluated the main statistical characteristics: mean, standard deviation, variance and the coefficient of variation. Which of these characteristics has it's unit square meter?
variance
standard deviation
mean
coefficient of variation

9000150501

Level: 
B
A man of height \(180\, \mathrm{cm}\) casts a \(200\, \mathrm{cm}\) shadow. At the same moment, a tree of an unknown height casts a \(35\, \mathrm{m}\) shadow. Find the height of the tree.
\(\frac{63} {2} \, \mathrm{m}\)
\(\frac{350} {9} \, \mathrm{m}\)
\(\frac{72} {7} \, \mathrm{m}\)
\(\frac{36} {35}\, \mathrm{m}\)

9000153308

Level: 
B
Statistical file contains repeating measurements of a body mass in kilograms. Find the change in the coefficient of variation if we convert all data in the file to grams.
The coefficient of variation does not change.
The coefficient of variation becomes bigger.
The coefficient of variation becomes smaller.

9000151307

Level: 
B
Find the angle \(\varphi \) between the line \(x + \sqrt{3}y - 6 = 0\) and the line \(p\) given by it's parametric equations. \[ p\colon \begin{aligned}[t] x& = 2 + t,& \\y& = 5;\ t\in \mathbb{R} \\ \end{aligned} \]
\(30^{\circ }\)
\(90^{\circ }\)
\(60^{\circ }\)
\(45^{\circ }\)

9000151306

Level: 
B
Find the angle \(\varphi \) between the lines \(p\) and \(q\) given by their parametric equations. \[ p\colon \begin{aligned}[t] x& = 1 - t, & \\y& = 2 + t;\ t\in \mathbb{R}, \\ \end{aligned}\qquad q\colon \begin{aligned}[t] x& = 4 - k, & \\y& = 5 + k;\ k\in \mathbb{R}. \\ \end{aligned} \]
\(0^{\circ }\)
\(90^{\circ }\)
\(60^{\circ }\)
\(30^{\circ }\)

9000149410

Level: 
B
Find all lines passing through the point \(A = [-2;-6]\) such that the distance from the point \([0.0]\) to these lines is \(2\sqrt{2}\).
\(p_{1}\colon 7x + y + 20 = 0\), \(p_{2}\colon x - y - 4 = 0\)
\(p\colon 7x - y = 0\)
\(p\colon x + y + 2\sqrt{2} = 0\)
\(p_{1}\colon x - y + 2\sqrt{2} = 0\), \(p_{2}\colon x + y - 2\sqrt{2} = 0\)