Final answer:
To be 95% confident that the sample mean is within $18 from the population mean, you need to include at least 821 tourists in your sample.
Step-by-step explanation:
In order to determine how many tourists should be included in your sample to be 95% confident that the sample mean is within $18 from the population mean, you need to use the formula for sample size calculation:
n = (Z * σ / E)^2
Where:
- n is the required sample size
- Z is the Z-score corresponding to the desired confidence level. For a 95% confidence level, it is 1.96
- σ is the known standard deviation ($62 in this case)
- E is the desired margin of error ($18 in this case)
Plugging in the values:
n = (1.96 * 62 / 18)^2 = 28.628^2 = 820.45
Therefore, you should include at least 821 tourists in your sample to be 95% confident that the sample mean is within $18 from the population mean.