In the following problem, the ratios are directly proportional. Find the missing variable. If y1 = 4, x2 = 6, and y2 = 8, what is the value of x1?

x1 = 3

Step-by-step explanation:

first set up the proportion (write as fractions):

(y1/x1) = (y2/x2)

then fill in the variables:

4/x1 = 8/6

now cross multiply:

8 • x1 = 6 • 4

simple algebra:

8 • x1 = 24

x1 = 24/8

x1 = 3

54 kilometers per hour

step-by-step explanation:

according to rules:

1 km = 1000 meter

which means that 1 meter = 1/1000 km

1 hour = 3600 second [ as 1 hour = 60 min = 60 *60 seconds ]

which means that 1 second = 1/3600 hour

therefore, 1 kilometer/hour =

thus to convert 15 meter per second to kilometer per hour, we multiply 15 to 3.6 kilometer/hour.

15 meter/second=   which is the required answer.