Judge the degree of support in each separate inference in these arguments. Give reasons in each case.

1. Motor vehicle manufacturers say that it is no longer necessary to warm up car motors before driving. Therefore, letting my new car's motor run for a few minutes before driving will not increase its effective life.

2. There were one hundred marbles in this jar, which were thoroughly stirred and mixed before sampling. The first forty marbles that I removed at random were white. Therefore, the remaining sixty are all white too.

3. There were fifty marbles in this jar, which were thoroughly stirred and mixed before sampling. The first forty-nine marbles that I removed at random were all white. Therefore, the remaining marble is white too.

4. The tanks on a ship carrying liquefied natural gas must have double walls and insulation more than a metre thick to reduce the rate of vapourisation. Accordingly, a collision that might lead to a loss of cargo would have to be considerably more severe than it would if the ship were built like a petroleum tanker, where the tank is the hull of the ship itself. So accidents like ramming and grounding are highly unlikely to cause the release of cargo from a ship carrying liquefied natural gas.