Which is the directrix of parabola with equation x^2=4y

A production manager tests 10 lightbulbs and finds their mean lifetime is 442 hours. She then designs a sales package for this type of bulb. It states that consumers can expect the bulb to last approximately 450 hours.

17. The first five students who arrived for the Tuesday lecture filled out a questionnaire on their attitudes toward statistics. The first five who were late for lecture were asked to fill out the same questionnaire.

Whats 261 divided by 5 with a remainder no decimals

If y = 7.2 when x = 10, what is the value of x when y = 20? (y varies inversely as the square of x.) A. 14.4 B. 6 C. 10 D. 20

Angle a is opposite to

Find the height of a triangle with an area (a) of 35 square inches and base (b) of 7 inches. Use the formula for the area of a triangle, a = 1/2bh

A survey of 50 people found that 14 people like building a snowman. If 600 people had responded, how many would have been expected to list building a snowman as their favorite winter activity? theoretical or experimental probability, and why

What is leaner equation

The probability of heads 3 times in a row is very low. if first two times are heads, what is the probability in 3rd

7y+25=-24 what is the answer