The Alto-Baxter affiliated group filed a consolidated return for the first time last year. The group does not come under the "large" corporation rules. For last year, the group reports a tax liability of $60,000. Cooper Corporation has a $30,000 tax liability last year. This year, the Alto-Baxter affiliated group purchased all of the Cooper stock. This year, the Alto-Baxter-Cooper group reports a $110,000 consolidated tax liability. To avoid penalties for the current year, the group must make timely estimated tax payments of how much during the year?