Statistics

9000153303

Level: 
C
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. Unit of which of these characteristics is meter?
the mean and the standard deviation
only the variance
only the standard deviation
only the mean
the standard deviation and the variance
the standard deviation, the variance and the coefficient of variation

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.

9000153310

Level: 
B
Student did repeated measurements of the coefficient of friction, which is a dimensionless quantity. The mean of the measurements is \(0.6\) and the coefficient of variation (relative error) \(10\%\). From statistics it is known that with a probability nearly \(100\%\) the value of the coefficient is in the interval centered at the mean and having radius equal to the triple of the standard deviation. Find the upper bound of this interval.
\(0.78\)
\(0.18\)
\(0.42\)
\(0.66\)

9000153304

Level: 
B
Two students performed repeated measurements of the same length. After evaluating statistical characteristics they got equal means of the length. Which of the following statement is true? (Remark: The accuracy is determined by the coefficient of variation.)
There is not enough information to compare the accuracy of both measurements.
One of the students measured with a better accuracy than the other.
Both students did their measurements with the same accuracy.

9000153305

Level: 
B
Two students performed repeated measurements of the same length. After evaluating statistical characteristics they got equal standard deviations. Which of the following statement is true? (Remark: The accuracy is determined by the coefficient of variation.)
There is not enough information to compare the accuracy of both measurements.
One of the students measured with a better accuracy than the other.
Both students did their measurements with the same accuracy.

9000153306

Level: 
B
Two students performed repeated measurements of the same length. After evaluating statistical characteristics they got equal means and also equal standard deviations. Which of the following statement is true? (Remark: The accuracy is determined by the coefficient of variation.)
Both students did their measurements with the same accuracy.
There is not enough information to compare the accuracy of both measurements.
One of the students measured with a better accuracy than the other.
The stated question is irrelevant, two different statistical files cannot share their means and their standard deviations.

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.
\(2\: 520\, \mathrm{g}\)
\(2\: 540\, \mathrm{g}\)
\(2\: 480\, \mathrm{g}\)
\(2\: 460\, \mathrm{g}\)

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.

9000139501

Level: 
A
Ten apples in a box have average mass \(200\, \mathrm{g}\). We remove one apple of the mass \(200\, \mathrm{g}\) from the box. What is the change in the average mass of the apples from the box?
The average mass of the apples does not change.
The average mass of the apples decreases by \(20\, \mathrm{g}\).
The average mass of the apples increases by \(20\, \mathrm{g}\).
There is not enough information to solve this problem.

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 \(12\, \mathrm{g}\).