> plot3 % + group_by(work_year, experience_level)%>% + summarize(average_salary = mean(salary_in_usd))%>% + ggplot(mapping = aes(x=work_year, y =average_salary, color = experience_level ))+ + geom_line()+ + labs(x =

> plot3 <- arshia%>% + group_by(work_year, experience_level)%>% + summarize(average_salary = mean(salary_in_usd))%>% + ggplot(mapping = aes(x=work_year, y =average_salary, color = experience_level ))+ + geom_line()+ + labs(x = "Year",y = "Average salary (USD)", + title = "Average salary by experience level over time - 2020-2022") `summarise()` has grouped output by 'work_year'. You can override using the `.groups` argument. > plot3 Error: Must request at least one colour from a hue palette.

how to remove this error