Final answer:
After applying the principle of inclusion-exclusion to the survey data, it is calculated that 252 investors out of 1,000 do not receive any version of the company newsletter.
Step-by-step explanation:
To determine how many investors do not receive the newsletter at all, we can use the principle of inclusion-exclusion. First, we add the total number of investors receiving the mail newsletter and those receiving the newsletter via email. Then, we subtract the number of investors who receive both to avoid counting them twice. Finally, we subtract this result from the total number of investors to find those who do not receive the newsletter at all.
605 (mail) + 452 (email) - 309 (both) = 748 investors receive at least one version of the newsletter.
Next, we subtract this number from the total number of investors:
1,000 (total investors) - 748 (receive newsletter) = 252 investors do not receive the newsletter at all.