Final answer:
Without the scatter plot data points, an accurate prediction cannot be made, but using historical data, the average US household spends about one-third of its budget on food. A specific prediction would require more detailed information for a household of seven.
Step-by-step explanation:
To predict the average amount of money spent on groceries for a household with seven people based solely on the scatter plot is not possible without specific data points from the plot. However, if we refer to historical patterns and the provided reference information, we can make an estimation.
According to the Bureau of Home Economics and Human Nutrition, the average family spent one-third of its income on food. Since Orshansky's model proposes that the poverty line be thrice the cost of a nutritionally adequate diet, it can be used for estimating food expenses based on family size. If we use information from the Consumer Expenditure Survey carried out by the U.S. Bureau of Labor Statistics, which states the average U.S. household spent $48,109 on consumption in 2015, with approximately one-third on food and vehicle expenses, it's possible to estimate the spending on food.
However, because these are broad statistics and averages, and household sizes and incomes vary, a more detailed scatter plot would be needed to make an accurate prediction specifically for a household of seven individuals.