1. We want to obtain a confidence interval for the mean of psychological processes that a psychologist does in a company in one day. For this we carry out a sample consisting of randomly chosen psychologists who carried out processes within the company in 10 different hours; the results were: average processes per day 15, and variance of said sample 4. Obtain said interval with a confidence level of 92% 2. The duration of psychological intervention in a clinic can be approximated by a normal distribution with a standard deviation of 5 minutes. A sample is taken randomly of 10 interventions and the following durations are obtained (in minutes): 35, 41, 25, 34, 29, 27, 34, 36, 40, 28 Find a confidence interval at 90% for the duration of a psychological intervention in the clinic. 3. A pharmaceutical company states that the number of hours that a medication takes time to cure a certain disease follows a normal variable with standard deviation equal to 13. A sample of 100 patients is taken from that they are administered the drug and it is observed that the average hours they take to cure equals 24. Find a confidence interval, with a confidence level of 85%, for the mean number of hours it takes for the drug to cure. 4. In a sample of 500 university students, 70% responded that they attend tutorials weekly. Between which values is found, with a confidence level of 95%, the proportion of university students who attend tutorials every week.