You dont need to answer the questions, I just need to know the formula and how to plug in the term to find the first term and to find a rule​

Select all of the following expressions that are equal to 2.5.

The weibull distribution is widely used in statistical problems relating to aging of solid insulating materials subjected to aging and stress. use this distribution as a model for time (in hours) to failure of solid insulating specimens subjected to ac voltage. the values of the parameters depend on the voltage and temperature; suppose α = 2.5 and β = 190. (a) what is the probability that a specimen's lifetime is at most 250? less than 250? more than 300? (round your answers to four decimal places.) at most 250 less than 250 more than 300 (b) what is the probability that a specimen's lifetime is between 100 and 250? (round your answer to four decimal places.) (c) what value is such that exactly 50% of all specimens have lifetimes exceeding that value? (round your answer to three decimal places.) hr

Kari plans to sample 20 people of a population that contains 100 students. she wants to determine how many people wake up before 6 a.m. which sample is the most random?