Are the ratios 3:4 and 6:8 equivalent

YES.

Step-by-step explanation:

Recall that multiplying both sides of a fraction by a number results in the same ratio. Therefore, 3:4 and 6:8 are equal ratios

Yes they are

Step-by-step explanation:

the ratio 3:4 is the same as 6:8 because they just multiplied both sides by 2 making it equivalent.

Hope this helps!

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.

the arc length is found by finding the circumference of the full circle (2xpixradius) and then dividing by 4 to find just one quarter of the circle (90 degrees).