According to Chad, all intersecting lines form right angles. If he's right, explain why.

A. Chad is correct because intersecting lines are always perpendicular.

B. Chad is incorrect because intersecting lines are never perpendicular.

C. Chad is incorrect because intersecting lines are sometimes perpendicular.

D. Chad is correct because intersecting lines are sometimes perpendicular.

Fran would like to estimate the mean amount of time it takes people in her town to travel to work. the town's population is 150,000 and about 90,000 of those are working adults. which statements are true? select each correct answer. there is no way to infer the value of the mean. she must collect data for all 90,000 working adults and calculate the mean. a larger sample of working adults will provide a better estimate of the true mean than a smaller sample. the population of working adults is too large for using a sample to estimate the mean of the entire group. if she takes a random sample of the population of working adults in her town, the mean for that group is likely close to the mean for the entire group.

Country carpets charges $22 per square yard for carpeting, and an additional installation fee of $100. city carpets charges $25 per square yard for the same carpeting, and an additional installation fee of $70

Two years ago a man was six times as old as his daughter. in 18 years he will be twice as old as his daughter. determine their present ages.