95% confidence interval would be (58.96, 69.04).
Step-by-step explanation:
Since we have given that
Number of dogs' weight = 20
Mean = 64 ounces
Standard deviation = 11.5 ounces
We need to find the 95% confidence interval.
So, z = 1.96
so, interval would be
[tex]\bar{x}\pm z\dfrac{\sigma}{\sqrt{n}}\\\\=64\pm 1.96\times \dfrac{11.5}{\sqrt{20}}\\\\=64\pm 5.04\\\\=(64-5.04,64+5.04)\\\\=(58.96,69.04)[/tex]
Hence, 95% confidence interval would be (58.96, 69.04).