Exam 4: Measures of Central Tendency and Variability

= 0

By changing the value of one score in a sample this will necessarily cause the mode to change.

What is the appropriate symbol for the formula:

A history professor gives a quiz to his class and records the following scores: 13, 11, 11, 9, 12, 13, 16, 14, 11, 10, 8, 13, 20. The mean for this distribution is _________.

If a group of 100 people has an average IQ of 107 and a group of 50 people has an average IQ of 101, the average IQ of all the people is 105.

In general, ΣX² = ( ΣX)²

Consider the same values as above except now each value is multiplied by 2. The results are: Miles per gallon: 62.4, 57.2, 72.8, 74.6, 60.2, 58.0, 65.4, 63.8

It is possible to have more than one mode in a sample of scores.

In a positively skewed distribution, the mean has a higher value than the median.

It is possible to have a set of scores with three different values for central tendency.

If one uses N instead of N - 1 in the denominator of the equation for the sample standard deviation, one will underestimate the population standard deviation.

In a skewed distribution, the mean and median are equal.

The median and the 50th percentile rank score will always have the same value.

Measures of variability quantify the extent of dispersion in a set of scores.

Of the measures of central tendency, the mean is the least subject to sampling variations.

Define mode.

The overall mean is a weighted mean.

The following IQ data has been obtained for 11 incoming graduate students: 120, 130, 132, 139, 160, 115, 120, 142, 148, 120, 141 Find each of the following statistics:

Given the following set of scores X : 10, 12, 6, 8, 9, 11, 13, 13, 5, 0, 1 What is the value of ?

By changing the value of one score in a sample this will necessarily cause the mean to change.