Question

Southwire is interviewing for a new senior position and is interested in knowing a salary range where most of the other competitors in their field are offering salaries, so they pay to get proprietary data of the industry offers. They receive 225 salaries, with sample mean of $85,000 and standard deviation of $15,000. Construct a 95% confidence interval around the sample mean (use a z-score for the critical value, i.e. row infinity of the t-table).

	$82,420 - $87,580
	$83,350 - $86,650
	$83,040 - $86,960
	$82,670 - $87,330

Answer 1

Given that,

Sample mean,

Sample standard deviation, s= 15000

n=225

The 95% confidence interval around the sample mean is given by,

From row infinity of the t-table,  

Then the confidence interval is given by,

the 95% confidence interval around the sample mean is given by,

($83,040 - $86,960)

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