Crop marks are used on an illustration to indicate to the printer the           a. center point of the illustration. b. position of screens, fills, and patterns. c. area of the illustration to reproduce. d. position of type in illustrations.

0.22hz

Step-by-step explanation:

Hi to answer this question we have to analyze the information given:

So, to calculate the frequency of the pendulum we have to apply the formula;

Frequency (f)= 1 / period  

Replacing with the value given:

f = 1/ 4.5 sec = 0.22 hz

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