The library sells 376 books at its annual used-book sale. the sale takes in a total of $2119. children's books cost $4 each, and adult books cost $7 each. let x = number of children's books sold, and let y = the number of adult books sold. write a system of equations to model this situation.

What situation is an example of an observational study

Atriangle has a side lengths of 18cm, 80 cm and 81cm. classify it as acute obtuse or right?

The fraction of defective integrated circuits produced in a photolithography process is being studied. a random sample of 300 circuits is tested, revealing 17 defectives. (a) calculate a 95% two-sided confidence interval on the fraction of defective circuits produced by this particular tool. round the answers to 4 decimal places. less-than-or-equal-to p less-than-or-equal-to (b) calculate a 95% upper confidence bound on the fraction of defective circuits. round the answer to 4 decimal places. p less-than-or-equal-to