The statement is false.
For confidence intervals, as the confidence level increases, the width of the interval generally increases as well. This is true for both averages (or means) and proportions.
In the case of averages, a higher confidence level implies a greater level of certainty, which requires a wider interval to accommodate the increased range of possible values.
Similarly, for proportions, increasing the confidence level leads to a wider confidence interval. The relationship between the confidence level and the width of the interval is generally the same for both averages and proportions.