Answer:
The margin of error of the poll is 8%.
Step-by-step explanation:
This is a confidence interval. A confidence interval has both a lower end and an upper end.
The true proportion is the midpoint between the two ends.
The margin of error is the absolute difference between the proportion and the ends(which is the same, upper end - proportion = proportion - lower end),
In this problem, we have that:
The lower end is 52%.
The upper end is 68%.
The proportion is (52 + 68)/2 = 60%.
The margin of error is 60 - 52 = 68 - 60 = 8%.
7. if you have a fraction with the same denominator, to add them together you add the numerators and the keep the denominator the same. to subtract, you subtract the numerator and keep the denominator the same.
8. the whole number times the denominator and add the answer to the numerator. to subtract you so the same just subtract rather than add
Answer:
All the plates were placed normally.
Step-by-step explanation:
All the plates were upside down, then every third waiter turned the third plate upwards, the fourth waiter turned every plate upward and so on, the pattern continued until the 100th waiter turned the 100th plate upward. The pattern was finished and all the plates were placed normally, right side up.
<span>15x + 35y - 40 z = 5 (3x + 7y -8z)
hope that helps
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Answer:
The bones were 12,485 years old at the time they were discovered.
Step-by-step explanation:
Amount of the element:
The amount of the element after t years is given by the following equation, considering the decay rate proportional to the amount present:

In which A(0) is the initial amount and k is the decay rate, as a decimal.
The radioactive element carbon-14 has a half-life of 5750 years.
This means that
, and we use this to find k. So







So

A scientist determined that the bones from a mastodon had lost 77.8 % of their carbon-14. How old were the bones at the time they were discovered?
Had 100 - 77.8 = 22.2% remaining, so this is t for which:

Then






The bones were 12,485 years old at the time they were discovered.