statistical methods

X The maximum acceptable noise level is 85.5 DB (decibels). A random sample of 10 measurements is taken during repair work on Saint-Joseph Street in Saint-Jerome, the results obtained are as follows 86 87 89 90 85 89 83 85 88 86 Assuming this variable normally distributed, Calculate a confidence interval at the 95% level for the average noise level on this street To answer the question, you must: ) Calculate the mean ~X b) Calculate the standard deviation o' x c) Determine the confidence interval d) Interpret this confidence interval Taking into consideration the maximum acceptable noise level which is 85.5 DB (decibel), can we say that on average the noise has exceeded significantly