Select Image Size from the Image menu item. Set the resolution to 72. Make sure the proportions are constrained and the file size is not. Change either the height or the width to the desired size.
Filter lists options for picture sharpening, softening, stylizing, distortion, etc.
To filter imported pictures first select RGB or CMYK color under the Mode menu item Image lists options for sizing, rotating, flipping, adjusting color, brightness, saturation, etc.