IF YOU GET GOOD GRADES ON TEST PLEASE HELP sarah hears the siren of an ambulance that is moving toward her. if the actual frequency of the siren is 2000 hertz; which frequency was heard by sarah?
A. 1900
B. 2000
C 1000
D. 2100
( please be 100% sure with your answer )

Lets say that an object of a certain volume has a certin mass. what happens to its mass when you double its volume?

Find the vertex(use the completing the square method), findthe x- and y-intercepts, and sketch the graph offunction. y = 2x2 + 4x - 1

Explain the difference between each pair of concepts. a. frequency and relative frequency b. percentage and relative frequency a. select the correct choice below. a. frequency is the total number of observations in a data set. relative frequency is the number of times a particular distinct value occurs. b. frequency is the number of times a particular distinct value occurs. relative frequency is the ratio of the frequency of a value to the total number of observations. c. frequency is the total number of observations in a data set. relative frequency is the ratio of the number of times a particular distinct value occurs to the frequency. d. frequency is the number of times a particular distinct value occurs. relative frequency is the ratio of the frequency of two different values.