Multiply in Scientific Notation Practice

Question

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Question
The average newborn weighs 7.5 pounds. About 4.1×106
babies are born in the United States every year. What is the approximate total weight in pounds of all the babies born in the U.S. in a year? Write the answer in scientific notation, expressed to the exact decimal place.(1 point)
pounds
Remaining Attempts : 3

Answer 1

To find the total weight of all the babies born in the U.S. in a year, you can multiply the average weight of a newborn by the number of babies born.

1. Average weight of a newborn = \( 7.5 \) pounds
2. Number of babies born = \( 4.1 \times 10^6 \)

Now, let's perform the multiplication:

\[ \text{Total weight} = \text{Average weight} \times \text{Number of babies} \] \[ \text{Total weight} = 7.5 \times (4.1 \times 10^6) \]

We can multiply the coefficients (the numbers before the powers of ten):

\[ 7.5 \times 4.1 = 30.75 \]

Now, we combine this with the \( 10^6 \):

\[ \text{Total weight} = 30.75 \times 10^6 \]

Next, we want to express \( 30.75 \) in scientific notation. We can write \( 30.75 \) as \( 3.075 \times 10^1 \).

Now, we can rewrite the total weight:

\[ \text{Total weight} = 3.075 \times 10^1 \times 10^6 \]

Using the properties of exponents, we combine these:

\[ \text{Total weight} = 3.075 \times 10^{1 + 6} = 3.075 \times 10^7 \]

Therefore, the approximate total weight in pounds of all the babies born in the U.S. in a year is:

\[ \boxed{3.075 \times 10^7} \]