{"blocks": [{"key": "e6e1f660", "text": "Scenario", "type": "header-two", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "0555b950", "text": "Out-of-home advertising campaign wants to estimate reach.", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "bdaa87f3", "text": "Question", "type": "header-two", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "51ff1d04", "text": "How would you estimate how many people actually saw a highway billboard and derive the total number of impressions it generated?", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "5f821216", "text": "Hints", "type": "header-two", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "941d324e", "text": "Segment the population, collect traffic counts or mobile-location samples, model exposure probability, then multiply by average views per person.", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}], "entityMap": {}}