Questions: The equation y=2(3^t) shows the number of infected people from an outbreak of the Norovirus. The variable y represents the number of infected people, and t represents time in weeks.
In how many weeks will the number of infected people reach 1,458?
a.) 5 weeks
b.) 10 weeks
c.) 6 weeks
d.) 12 weeks
Transcript text: The equation $y=2\left(3^{t}\right)$ shows the number of infected people from an outbreak of the Norovirus. The variable $y$ represents the number of infected people, and t represents time in weeks.
In how many weeks will the number of infected people reach $1,458 ?$
a.) 5 weeks
b.) 10 weeks
c.) 6 weeks
d.) 12 weeks
Solution
Solution Steps
Step 1: Start with the general equation
Given the exponential growth model, the equation is \(y = a \cdot b^t\), where:
\(y\) is the quantity of interest (number of infected people),
\(a\) is the initial quantity at \(t = 0\),
\(b\) is the growth factor per time unit,
\(t\) is the time in appropriate units (weeks).
Step 2: Solve for \(t\) when \(y\) is given
Rearrange the equation to solve for \(t\): \(t = \frac{\log(y/a)}{\log(b)}\).
Step 3: Substitute the given values into the equation
Substitute \(a = 2\), \(b = 3\), and \(y = 1458\) into the equation to get \(t\).
Step 4: Calculate \(t\)
Using the values, \(t = \frac{\log(1458/2)}{\log(3)} = 6\).
Final Answer:
The time \(t\) when the quantity of interest \(y\) is reached is approximately 6 weeks.