Final answer:
The probability of selecting a card with a number 4 from a well-shuffled deck of 52 cards without replacement is 1/13.
Step-by-step explanation:
To calculate the probability of selecting a card with a number 4 from a well-shuffled deck of 52 cards without replacement, you need to find the number of favorable outcomes and divide it by the total number of possible outcomes.
In a deck, there are 4 number 4 cards. So, the number of favorable outcomes is 4. The total number of possible outcomes is 52 since there are 52 cards in the deck.
Therefore, the probability of selecting a card with a number 4 is 4/52 which simplifies to 1/13.