I recently conducted a survey on Lucid and posed a short quiz to test basic numeracy:

A man writes a check for $100 when he has only $70.50 in the bank. By how much is he overdrawn? — $29.50, $170.50, $100, $30.50

Imagine that we roll a fair, six-sided die 1000 times. Out of 1000 rolls, how many times do you think the die would come up as an even number? — 500, 600, 167, 750

If the chance of getting a disease is 10 percent, how many people out of 1,000 would be expected to get the disease? — 100, 10, 1000, 500

In a sale, a shop is selling all items at half price. Before the sale, the sofa costs $300. How much will it cost on sale? — $150, $100, $200, $250

A second-hand car dealer is selling a car for $6,000. This is two-thirds of what it cost new. How much did the car cost new? — $9,000, $4,000, $12,000, $8,000

In the BIG BUCKS LOTTERY, the chances of winning a $10 prize are 1%. What is your best guess about how many people would win a $10 prize if 1000 people each buy a single ticket from BIG BUCKS? — 10, 1, 100, 50

I surveyed 800 adult Americans. Of the 800, only 674 respondents (about 84%) cleared the attention check—a question designed to test if the respondents were paying attention or not. I limit the analysis to these 674 respondents.

A caveat before the results. I do not adjust the scores for guessing.

Of these respondents, just about a third got all the answers correct. Another quarter got 5 out of 6 correct. Another 19% got 4 out of 6 right. The remaining 20% got 3 or fewer questions right. The table below enumerates the item-wise results.

Item

Proportion Correct

Overdraft

.83

Dice

.68

Disease

.88

Sofa Sale

.97

Car

.66

Lottery

.63

The same numbers are plotted below.

p.s. You may be interested in reading this previous blog based on MTurk data.