Measures of center and variation can be used to describe data sets. Choose ALL statements about these measures that are true. The mean, or average is a measure of center
The range of data set is a measure of center
The median of a data set is a measure of variability.
Measures of variability describe how the values in a data set vary.
Measures of Center describe all values in a data set with a single number

Statements reasons 1. ab ≅ cd; ad ≅ bc 1. given 2. ac ≅ ac 2. reflexive property 3. △adc ≅ △cba 3. ? 4. ∠dac ≅ ∠bca; ∠acd ≅ ∠cab 4. cpctc 5. ∠dac and ∠bca are alt. int. ∠s; ∠acd and ∠cab are alt. int. ∠s 5. definition of alternate interior angles 6. ab ∥ cd; ad ∥ bc 6. converse of the alternate interior angles theorem 7. abcd is a parallelogram 7. definition of parallelogram what is the missing reason in step 3?