Astudent measured the lead content of a paint sample 4 times. the standard deviation of the measurements was found to be 1.1% of the average. can this student be 90% confident that the true value is within 1.8% of the measured average?

Find the quotient. 50a2 – 98b2 -5a +7b

Hey hotel charges guests $19.75 a day to rent five video games at this rate which expression can be used to determine the charge for renting nine video games for one day at this hotel? pls

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?