Answer:
The length of a 95% confidence interval for mean Age is 3.72.
Step-by-step explanation:
The data is provided for the age of 100 adults.
The mean and standard deviation are:
[tex]\bar x=47.8\\\\s=9.3744[/tex]
As the sample size is too large the z-interval will be used for the 95% confidence interval for mean.
The critical value of z for 95% confidence level is, z = 1.96.
The length of a confidence interval is given by:
[tex]\text{Length}=2\cdot z_{\alpha/2}\cdot\frac{s}{\sqrt{n}}[/tex]
[tex]=2\times 1.96\times\frac{9.3744}{\sqrt{100}}\\\\=3.6747648\\\\\approx 3.67\\\\\approx 3.72[/tex]
Thus, the length of a 95% confidence interval for mean Age is 3.72.