Over the past 50 years, records for one northwest city show that rain fell on the first day of spring [tex]\frac{1}{3}[/tex] of the time. If you choose a year at random, what are the chances that the first day of spring will be a rainy Wednesday?

\begin{tabular}{|c|c|}
\hline Method & Count the number of times you \\
\hline Roll and spin 50 times & Roll a 1 or 6 and land on red. \\
\hline
\end{tabular}
\begin{tabular}{|c|c|}
\hline Method & Count the number of times you \\
\hline Roll 3 times & Roll greater than 2. \\
\hline Spin 7 times & Land on green. \\
\hline
\end{tabular}
\begin{tabular}{|c|c|}
\hline Method & Count the number of times you \\
\hline Roll 3 times. & Roll a 2. \\
\hline Spin 7 times. & Land on green. \\
\hline
\end{tabular}
\begin{tabular}{|c|c|}
\hline Method & Count the number of times you \\
\hline Find and spin 50 times. & Roll a 3 and land on red. \\
\hline
\end{tabular}



Answer :

Certainly! Let's go through the solution step-by-step:

1. Determine the Probability of Rain on the First Day of Spring:
From the historical data given, it is noted that rain fell on the first day of spring [tex]\(\frac{1}{3}\)[/tex] of the time. Therefore, the probability of rain on the first day of spring is:
[tex]\[ \text{P(Rain on the first day of spring)} = \frac{1}{3} \approx 0.3333 \][/tex]

2. Determine the Probability of the First Day of Spring Being Wednesday:
There are 7 days in a week, making each day equally likely to be the first day of spring. Therefore, the probability that the first day of spring falls on a Wednesday is:
[tex]\[ \text{P(Wednesday)} = \frac{1}{7} \approx 0.1429 \][/tex]

3. Calculate the Joint Probability of Both Events Happening:
To find the probability that the first day of spring is both rainy and falls on a Wednesday, we multiply the probabilities of the two independent events. Thus:
[tex]\[ \text{P(Rain on Wednesday)} = \text{P(Rain on the first day of spring)} \times \text{P(Wednesday)} = \frac{1}{3} \times \frac{1}{7} \][/tex]
Substituting in the values, we get:
[tex]\[ \text{P(Rain on Wednesday)} = \left(\frac{1}{3}\right) \times \left(\frac{1}{7}\right) = \frac{1}{21} \approx 0.0476 \][/tex]

So, the probability that the first day of spring will be a rainy Wednesday is approximately [tex]\(0.0476\)[/tex], which can also be expressed as [tex]\(\frac{1}{21}\)[/tex] or approximately 4.76%.