The data below were obtained from an experiment were participants were given drinks with or without caffeine and then asked to tap their fingers. The data for 20 participants are below. Assume the number of taps per minute is normally distributed. The variance is unknown. Find a 95% CI for μ number of taps. Identify the pivot function used. 246 242 248 245 250 244 252 248 248 247 250 248 246 242 248 244 245 246 250 242

The  95% confidence interval is    

The pivot function used is  

Step-by-step explanation:

From the question we are told that

  The  data given is 246 242 248 245 250 244 252 248 248 247 250 248 246 242 248 244 245 246 250 242

  The  sample  size is  

Given that the confidence level is 95% then the level of significance is

The  degree of freedom is mathematically represented as

From the student t-distribution table  the critical value of    is  

The mean is mathematically represented as

The standard deviation is mathematically represented as

The margin of error is mathematically represented as

The 95% confidence interval is mathematically represented as

=>  

=>      

The pivot function used is  

C. 16%

In short, the correct selection would be answer 16%