What is the weighted mean if scores are 4, 6, 8 with weights 1, 2, 3 respectively?

The median of an even number of observations is:

A bag contains 3 red balls and 5 blue balls. What is the probability of drawing a red ball?

What is the mean of the data 12, 18, 24, 30?

What is the class mark of the interval 25-35?

The estimated probability of an event based on 100 trials is 0.4. How many times did the event occur?

In a data set, the value that occurs most frequently is the:

What is the class midpoint of the interval 20-30?

If the mean of 4 observations is 15 and three observations are 12, 16, 18, what is the fourth observation?

In probability, the sum of the probabilities of all possible outcomes is: