Explain how estimation you place the decimal point when multiplying 3.9 & 5.3

Each morning papa notes the birds feeding on his bird feeder. so far this month he has see. 59 blue jays, 68 black crows, 12 red robin's and 1 cardinal. what is the probability of a blue jay being the next bird papa sees

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If private savings 'v' = 0.75s and total savings 's' equals $4.20 billion, solve for public and private savings.