Which describes independent events?

Spinning two fours on a spinner divided into four numbered sections.

Selecting two kings from a standard deck of cards by choosing a card at random, placing it in your pocket, then choosing the second card.

Selecting two green marbles by choosing one from a bag at random, giving the first to a friend, then choosing another.

Selecting the names of two siblings by choosing slips of paper from a hat at random, pinning the selected slip on a bulletin board, and then selecting another.

Question

Which describes independent events?

Spinning two fours on a spinner divided into four numbered sections.

Selecting two kings from a standard deck of cards by choosing a card at random, placing it in your pocket, then choosing the second card.

Selecting two green marbles by choosing one from a bag at random, giving the first to a friend, then choosing another.

Selecting the names of two siblings by choosing slips of paper from a hat at random, pinning the selected slip on a bulletin board, and then selecting another.

kropot72 · Answer

Two events are independent if the occurrence of one has absolutely no effect on the occurrence of the other. Therefore sampling without replacement does not result in a series of independent events.