4. To find the probability of rolling a number less than 4 on a standard cube, we need to determine how many outcomes satisfy the condition (rolling a number less than 4) and divide it by the total number of possible outcomes.
There are three numbers less than 4 on a standard cube, which are 1, 2, and 3. Therefore, there are three outcomes that satisfy the condition. The cube has a total of six possible outcomes (numbers 1-6), so the probability is 3/6, which simplifies to 1/2. Therefore, the correct answer is 1/2.
5. To find the experimental probability of rolling a two or three on a number cube rolled 360 times, we need to determine the number of times a two or three was rolled and divide it by the total number of rolls.
According to the given results, the number of times a two was rolled is 54, and the number of times a three was rolled is 62. To find the total number of rolls, we sum up the results for each number: 41 + 54 + 62 + 74 + 33 + 95 = 359.
Now, to find the experimental probability, we add the number of times a two was rolled (54) to the number of times a three was rolled (62): 54 + 62 = 116. We divide this sum by the total number of rolls (359): 116/359 โ 0.322. Rounded to two decimal places, this gives us 0.32. Therefore, the correct answer is 0.32.