Answer: Approximately 191 bees
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Work Shown:
One way to express exponential form is to use
y = a*b^x
where 'a' is the initial value and 'b' is linked to the growth rate.
Since we're told 34 bees are there initially, we know a = 34.
Then after 4 days, we have 48 bees. So we can say,
y = a*b^x
y = 34*b^x
48 = 34*b^4
48/34 = b^4
24/17 = b^4
b^4 = 24/17
b = (24/17)^(1/4)
b = 1.090035
Which is approximate.
The function updates to
y = a*b^x
y = 34*(1.090035)^x
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As a way to check to see if we have the right function, plug in x = 0 and we find:
y = 34*(1.090035)^x
y = 34*(1.090035)^0
y = 34*(1)
y = 34
So there are 34 bees on day 0, ie the starting day.
Plug in x = 4
y = 34*(1.090035)^x
y = 34*(1.090035)^4
y = 34*1.4117629
y = 47.9999386
Due to rounding error we don't land on 48 exactly, but we can round to this value.
We see that after 4 days, there are 48 bees.
So we confirmed the correct exponential function.
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At this point we can find out how many bees there are expected to be after 20 days.
Plug in x = 20 to get
y = 34*(1.090035)^x
y = 34*(1.090035)^20
y = 190.672374978452
Round to the nearest whole number to get 191.
There are expected to be roughly 191 bees on day 20.