Country S has 12,345,000 residents who tested positive for COVID-19. What is the largest place value of the numeric part of this quantity?(1 point)
million
The largest place value of the numeric part of 12,345,000 is million.
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
0.00002
0.00002
0.01
0.01
0.00003
0.00003
0.03
The best estimation of the quantity 0.000027503 of a year would be 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 the number 7,803,100 to the nearest place value, we look at the digit in the next smallest place value, which is the thousands place (0 in this case). Since it is less than 5, we round down the value in the hundreds place to 7,800,000.
To express this number in the form of a single digit times an integer power of 10, we can write it as 7.8 × 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 2×103 visits were reflected in their logbook during this two-week period, while only about 5×102 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 find the number of times higher the visits before the examination day compared to an average week, we can divide the number of visits before the examination day by the number of visits in an average week.
Number of visits before examination day: 2 × 10^3
Number of visits in an average week: 5 × 10^2
Dividing the number of visits before the examination day by the number of visits in an average week:
(2 × 10^3) / (5 × 10^2) = (2/5) × (10^3 / 10^2) = (2/5) × 10 = 0.4 × 10 = 4
Therefore, the number of library visits before the examination day is 4 times higher compared to the number of visits in an average week.
It 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×10n where a
is single digit.(1 point)
To find the amount in the form of a×10n, we can round $15,528.23 to the nearest place value and then express it in scientific notation.
Rounding $15,528.23 to the nearest place value gives us $15,528.
To express this amount in the form of a×10n, we divide it by 10,000 and get:
$15,528 / 10,000 = 1.5528
Next, we can express this in scientific notation by moving the decimal point one place to the right and multiplying it by 10 raised to the power of 4, resulting in:
1.5528 × 10^4
Therefore, $15,528.23 can be expressed as 1.5528×10^4.