Statistics

9000139502

Level: 
A
The average mass of \(30\) eggs on a plate is \(60\, \mathrm{g}\). From this amount we remove five eggs. The total mass of these five eggs is \(280\, \mathrm{g}\). Find the change in the average mass of the remaining eggs on the plate.
The average mass of eggs increases by \(0.8\, \mathrm{g}\).
The average mass of eggs decreases by \(4\, \mathrm{g}\).
The average mass of eggs increases by \(4\, \mathrm{g}\).
The average mass of eggs increases by \(12\, \mathrm{g}\).

9000139503

Level: 
A
The average mass of the pear in a basket is \(150\, \mathrm{g}\). Find the change in the average mass of the pears in the basket if one pear has been removed from the basket.
There is not enough information to solve this problem.
The average mass of the pears increases by \(7.5\, \mathrm{g}\).
The average mass of the pears decreases by \(7.5\, \mathrm{g}\).
The average mass of the pears does not change.

9000139504

Level: 
A
The average salary of five employees is \(3\: 000\, \mathrm{Euro}\). This group of the employees is expanded by one new person. The salary of the new person is \(2\: 400\, \mathrm{Euro}\). Find the change in the average salary of this group.
The average salary decreases by \(100\, \mathrm{Euro}\).
The average salary decreases by \(480\, \mathrm{Euro}\).
The average salary increases by \(400\, \mathrm{Euro}\).
The average salary increases by \(480\, \mathrm{Euro}\).

9000139505

Level: 
A
The average mass of twelve oranges is \(120\, \mathrm{g}\). To this amount we add another six oranges with the average mass \(150\, \mathrm{g}\). Find the change in the average mass of oranges.
The average mass increases by \(10\, \mathrm{g}\).
The average mass increases by \(8.3\, \mathrm{g}\).
The average mass increases by \(25\, \mathrm{g}\).
The average mass decreases by \(8.3\, \mathrm{g}\).

9000139506

Level: 
A
There are eight mandarins of average mass \(90\, \mathrm{g}\) in the box. We got two another mandarins and add them to the box. The new average mass of the mandarins in the box is \(92\, \mathrm{g}\). Find the average mass of the two added mandarins.
\(100\, \mathrm{g}\)
\(92\, \mathrm{g}\)
\(96\, \mathrm{g}\)
\(106\, \mathrm{g}\)

9000139507

Level: 
A
The average mass of five melons is \(2\: 400\, \mathrm{g}\). We have to add another melon such that the new average value of all six melons will be \(2\: 420\, \mathrm{g}\). Find the mass of the sixth melon.
\(2\: 520\, \mathrm{g}\)
\(2\: 540\, \mathrm{g}\)
\(2\: 480\, \mathrm{g}\)
\(2\: 460\, \mathrm{g}\)

9000139509

Level: 
A
The average year income in a company was \(200\: 000\, \mathrm{Euro}\) two years ago. This income increased by \(10\%\) a year ago and by \(80\: 000\, \mathrm{Euro}\) this year. Find the average percentage increase in the average income per one year and round to the nearest percent.
\(22\%\)
\(23\%\)
\(25\%\)
\(50\%\)

9000139510

Level: 
A
The price of a butter increased by \(8\%\) in the year \(2013\) and by \(34\%\) in the year \(2014\). Find the average percentage growth of the price of the butter per one year in the period \(2012\)-\(2014\). Round your answer to the nearest percent.
\(20\%\)
\(21\%\)
\(14\%\)
\(26\%\)

1003025201

Level: 
B
Two hunters, Adam and Boris, competed in target shooting. Adam hit the target points \( \{10;10;9;8;7\}\), and Boris \( \{10;10;9;9;6\} \). Who is the winner? In the case of the same sum of gained points the shooting accuracy is decisive. Which of the following statements is true, if the accuracy is quantified by the variance of the points? (The variance is rounded to two decimal places.)
Adam won with the variance of \( 1{.}36\,\mathrm{points}^2 \).
Adam won with the variance of \( 1{.}17\,\mathrm{points}^2 \).
Boris won with the variance of \( 2{.}16\,\mathrm{points}^2 \).
Adam won with the variance of \( 1{.}36\,\mathrm{points} \).
Adam won with the variance of \( 1{.}17\,\mathrm{points} \).
Boris won with the variance of \( 2{.}16\,\mathrm{points} \).

1003029401

Level: 
B
Wooden boards were expected to be cut to the same length. After their cutting the resulting measured lengths are: \( 2{.}00;\ 2{.}02;\ 2{.}05;\ 2{.}02;\ 2{.}08;\ 2{.}11 \) (in meters). We use the standard deviation of board lengths to describe (quantify) the accuracy of cutting. Find the standard deviation of board lengths rounded to four decimal places.
\( 0{.}0382\,\mathrm{m} \)
\( 0{.}0381\,\mathrm{m} \)
\( 0{.}0014\,\mathrm{m} \)
\( 0{.}0015\,\mathrm{m} \)