To estimate the number of COVID-19 cases in the UK on day 22 using the described graph, you would need to identify the y-value (total number of cases) corresponding to “day 22” on the x-axis.
Without the ability to see the actual graph, I can't provide the exact number. However, you can look at the graph to find the point on the y-axis that corresponds to day 22.
Once you have that visual representation, you can choose the option that closely matches the value from the graph on that day. If you’re estimating and can't see the graph but are considering the options provided, you might want to look at the trends in the data leading up to day 22.
Among the options provided: 30,000 cases, 25,000 cases, 3,500 cases, and 21,000 cases, you would select the number nearest to what the graph indicates for day 22.
If I had to suggest an estimate based on typical case growth curves during that time, it might more likely be in the range of 3,500 to 30,000. Check the graph carefully and see which of those options aligns with what you observe for day 22.