Question

1. the lowest score subtracted from highest score in a set of data is called the
2. the extent to which an instrument (test) measures or predicts what it is supposed to. example - your next test in this class should be about experimental psychology, not american history....because your next text will have
3. the numerical value showing the degree of correlation between two variables; which is symbolized by the letter r is called the
4. what am i describing? chance is less than 5 in 100 (<.05), resulting conclusion in not influenced by chance. this shows whether the results are likely due to the iv or merely due to chance. this is called
5. a __________ correlation occurs when one variable increases and the other variable decreases and a __________ correlation occurs when both variables move in the same direction.
6. calculate the mean, mode, median, and range of the following set of numbers. (5,5,2,4,6,8) show your work.

a. median-
b. mode-
c. mean-
d. range-

Explanation:

Step1: Define range

The range of a data - set is calculated as the highest value minus the lowest value.

Step2: Define validity

Validity refers to the extent to which a test measures what it is supposed to measure.

Step3: Define correlation coefficient

The correlation coefficient, denoted by \(r\), measures the degree of correlation between two variables.

Step4: Define statistical significance

Statistical significance is determined when the probability (p - value) is less than a certain threshold (commonly 0.05), indicating that the results are likely not due to chance.

Step5: Define types of correlation

A negative correlation occurs when one variable increases and the other decreases, and a positive correlation occurs when both variables move in the same direction.

Step6: Calculate median

First, order the data set \(\{2,4,5,5,6,8\}\). Since there are 6 numbers (an even number of data - points), the median is the average of the two middle numbers. \(\text{Median}=\frac{5 + 5}{2}=5\).

Step7: Calculate mode

The mode is the number that appears most frequently in the data set. Here, the number 5 appears twice, more frequently than other numbers, so \(\text{Mode}=5\).

Step8: Calculate mean

The mean \(\bar{x}=\frac{5 + 5+2 + 4+6 + 8}{6}=\frac{30}{6}=5\).

Step9: Calculate range

The highest value is 8 and the lowest value is 2. So, \(\text{Range}=8 - 2=6\).

Answer:

1. Range
2. Validity
3. Correlation coefficient
4. Statistical significance
5. Negative; Positive

26.
a. Median: 5
b. Mode: 5
c. Mean: 5
d. Range: 6