Answer:
The test statistic is 
Step-by-step explanation:
From the question we are told that
The population mean is 
The The level of significance is 
The sample size is n = 18
The null hypothesis is 
The alternative hypothesis is 
The sample mean is 
The standard deviation is 
Generally the test statistics is mathematically represented as

substituting values


72 is the volume because u multiply 12 times two then multiply by 6
Answer:
The answer should be B.
Step-by-step explanation:
Btw a school orchestra should usually contain only string instruments and whatnot. If it has woodwinds, brass instruments, and percussion, then that would be a band.