If the mean of these numbers is 6 what is x ? 6,3,x, 10

If the ratio of sum of the first m and n terms of an ap is m2 : n2 , show that the ratio of its mth and nth terms is (2m − 1) : (2n − 1).

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?

If the car had not hit the fence, how much farther would it have skidded? solve the skid-distance formula to find the extra distance that the car would have traveled if it had not hit the fence. round your answer to two decimal places. note that unit conversion is built into the skid distance formula, so no unit conversions are needed.