Ask a New Question
Menu

The time it takes the population of a microorganism to reduce by half is 0.000027503 of a year. What number is the best estimation of this quantity?(1 point) Responses

0.00003
0.00002
0.03
0.01

7 answers

To estimate the value of 0.000027503, let's round it to a more manageable form:

  • Look at the first few significant figures: 0.000027503 is approximately between 0.00002 and 0.00003.
  • Comparing the two, 0.000027503 is closer to 0.00003.

So, the best estimation of the quantity is:

0.00003

A total of 7,803,100 tourists visited Country A from the year 2018 to the year 2020. Round to the nearest place value, then express this number in the form of a single digit times an integer power of 10.(1 point)

To round 7,803,100 to the nearest place value, we need to consider the millions place value, since the number is in the millions.

  1. The first step is identifying the place values:

    • The millions place is 7 (for 7,000,000).
    • The hundred thousands place is 8 (for 800,000).

  2. Since the hundred thousands place (8) is 5 or greater, we round up the millions place (7) to 8.

Thus, rounding 7,803,100 gives us 8,000,000.

Now, to express this number in the form of a single digit times an integer power of 10:

8,000,000 = 8 × 10^6.

So the final answer is:

8 × 10^6.

Two weeks before an examination day, a librarian monitored the number of students who visited the library. Then they compared it with the number of visits made in an average week. Approximately 2×10^3 visits were reflected in their logbook during this two-week period, while only about 5×10^2 were reflected on an average week. How many times higher is the number of library visits before examination day compared to the library visits in an average week? Your answer should be a whole number.(1 point)

To determine how many times higher the number of library visits before examination day (2 × 10^3) is compared to the average weekly visits (5 × 10^2), we can perform the following calculation:

  1. Find the total number of visits in the two-week period:

    • 2 × 10^3 = 2000 visits

  2. Find the average weekly visits:

    • 5 × 10^2 = 500 visits

  3. Calculate how many times higher the two-week visits are compared to the average weekly visits:

    • We can divide the total visits during the two-week period by the average weekly visits: \[ \text{Number of times higher} = \frac{2000}{500} \]

  4. Perform the division: \[ \frac{2000}{500} = 4 \]

Thus, the number of library visits before examination day is 4 times higher than the average weekly visits.

takes 10 years for a $100 monthly bank deposit to amount to $15,528.23 when invested at 5% interest compounded monthly. Round to the nearest place value, then express the amount $15,528.23 in the form of a×10^n where a is single digit.(1 point)

To express the amount $15,528.23 in the form \( a \times 10^n \) where \( a \) is a single digit, we will first identify the scientific notation.

  1. Identify the significant figures:

    • The first digit of 15,528.23 is 1.
    • We can express 15,528.23 as 1.552823.

  2. Determine the exponent:

    • To convert 1.552823 into scientific notation, we move the decimal point two places to the right to get 15.52823.
    • Thus, in scientific notation, we need to adjust by multiplying by \( 10^2 \).

  3. Final expression:

    • So, we can write: \[ 15,528.23 = 1.552823 \times 10^4. \]
    • Rounding \( 1.552823 \) to one significant digit gives us \( 1.6 \).

  4. Thus, the final expression is: \[ 1.6 \times 10^4 \]

So, the amount \( 15,528.23 \) can be expressed as 1.6 × 10^4.