Question

The speed of 10 Ferris wheels is sampled. The speed, measured in miles per hour, are

Answer 1

Answer:

The best estimate if the mean, this is the arithmetic average: 11.4 mph


Justification:


1) Calculation of the mean:

Mean = ∑ of indivitual values / number of values.

∑ of indiviual values = 10 + 10 + 12 + 14 + 10 +  9 + 8 + 14 + 12 + 15 = 114


Number of values = 10


Mean = 114 / 10 = 11.4 mph


2) Other possible estimates would be the median and the mode. But those statistics are not best estimates.


Only if there are outliers, and you are not able to identify them in the sample, the mean calculated with all the values would not be the best estimate.


The given set of data does not show any outliers, so the calculated mean is the best estimate.


3) Just for reference the mode is 10, as it is the number that is repeated most times.


And the median is the average of the two values in the middle (for an even number of data). To determine the median you first order the values, in increasing or decreasing form. This is: 8, 9, 10, 10, 10, 12, 12,14, 14, and 15.

So the two middle values are 10 and 12, and their average is 11.


So, the three possible estimates are:

Mean: 11.4 mph
Median: 11.5 mph
Mode: 10 mph.

The mean is the statistics in which you must rely the most, as it is intended to minimize the errors.