Final answer:
To find the probability in a t-distribution, use the ALEKS calculator or the inverse CDF function.
Step-by-step explanation:
(a) Using the ALEKS calculator, we can determine the value of P(t ≤ -1.3) for a t-distribution. Round your answer to three decimal places.
To find this probability, we need to calculate the cumulative distribution function (CDF). The CDF gives us the probability of a random variable being less than or equal to a specific value. In this case, we want to find P(t ≤ -1.3).
(b) For a t-distribution with 5 degrees of freedom, we need to find the value of 'c' such that P(-c < t < c) equals 0.90. Round your answer to at least three decimal places.
To find this value of 'c', we need to use the inverse CDF function. This function gives us the value of 'c' that corresponds to a certain probability. In this case, we want to find the value of 'c' such that the probability between -c and c is 0.90.