In many methods that employ multiple measurements, one particular type of measurement may be the "weak link that limits overall precision. For the density measurements you made here, you will determine what contributes most to the CV of your calculated density - the measurements of mass or of dimensions. Typical standard deviation for length and mass using the equipment employed are the following: Dimensions: 0.01 cm
Mass: 0.0029
Diameter (cm): 1.12
Height (cm): 1.69
Mass (cm): 4.020
Volume (cm3): 1.66
Density (g/cm3): 2.42
Select the data for your lightest object focusing on its mass and its shortest dimension.
A. What is the CV for the mass value?
B. What is the CV for the measurement of its shortest dimension?
C. Which type of measurements (mass or dimensions) had the greatest impact on the CV of the measured density?
1. Mass measurements have the greater impact because the mass CV with lightest object was greater than its dimension CV.
2. Mass measurements have the greater impact because the mass CV with lightest object was lesser than its dimension CV.
3. Dimension measurements have the greater impact because the dimension CV with lightest object was greater than its mass CV.
4. Dimension measurements have the greater impact because the dimension CV with lightest object was lesser than its mass CV.

pre-sliced bread is a relatively recent development in baking technology. previous to that, it was always sold in a bakery in daily-made contiguous loaves with no wrapping, and was moderately perishable, usually being used with a day or two (which is why every bakery had a discounted “day-old” bread table.) therefore, pre-sliced bread would grow stale quickly. the hard crust provided a protective layer, and once the exposed dry slice left from the previous cut was removed, the interior was still soft.

what keeps bread soft is the moisture retained in the crumb (the light spongy part that’s not crust). the reason the crust develops is the surface of the dough gets exposed to hot dry air during baking which browns the outer layer and seals it, preventing all the moisture from escaping the dough. longer exposure to air will also eventually cause your bread to lose flavor and become stale.

people were used to cutting slices as they needed them and storing bread in a specially-made wooden or metal breadbox or pail with a lid to preserve it longer, but the first automatically sliced commercial loaves were produced on july 6, 1928, in chillicothe, missouri, using a machine invented by otto rohwedder, an iowa-born, missouri-based jeweler.[1] pre-sliced bread would indeed dry out, were it not for another 20th century technology: the plastic bag. bread could now be pre-sliced, and if the enclosing bag remains sealed as much as possible, the bread will remain soft and fresh for longer than if sitting unwrapped on a shelf or enclosed in a bread box that is not air-tight. sealed packaging meant bread could also be sold on store shelves and eliminate frequent trips to a bakery.

sealing bread in a plastic bag had another effect: the moisture in the loaf will re-distribute into the crust and soften it, which is sometimes more pleasing in a sandwich - especially for children whose teeth might not yet be strong enough to tear through a hard crust. a homemade loaf of bread can be sealed in a bag overnight and the crust will become soft like store-bought sandwich bread.

these were novel changes in how bread was produced and sold, which led to the coining of the phrase “the greatest thing since sliced bread.”

qualitative observation deals with data that can be observed with our senses: sight, smell, touch, taste, and hearing. they do not involve measurements or numbers. for instance, colors, shapes, and textures of objects are all qualitative observations.