Find the standard deviation of the thickness of an item.

1.  Two batteries, with voltages V1 and V2 , are connected in series. The total voltage V is given by V = V1 + V2 . Assume that V1 has mean 12 V and standard deviation 1 V, and that V2 has mean 6 V and standard deviation 0.5 V.

a.  Find μV . Assuming V1 and V2 to be independent,

b.  find σV .


2.   A laminated item is composed of five layers. The layers are a simple random sample from a population whose thickness has mean 1.2 mm and standard deviation 0.04 mm.

a.  Find the mean thickness of an item.

b.  Find the standard deviation of the thickness of an item.



3.  Two independent measurements are made of the lifetime of a charmed strange meson. Each measurement has a standard deviation of 7×10 −15 seconds. The lifetime of the meson is estimated by averaging the two measurements. What is the standard deviation of this estimate?


find the cost of your paper

Determine the outlet concentration x1 in the water solution and in the trichloroethane solution using an analytical equation.

Predicting Extraction for an Existing Tower with a Given Number of Steps. An existing tower contains 5.0 theoretical steps. It is desired to predict its performance under the following conditions….

Calculate the minimum solvent that can be used. [Hint: In this case, the tie line through the feed L0 represents the condition for minimum solvent flow rate.

Minimum Solvent and Countercurrent Extraction of Acetone. An aqueous feed solution of 1000 kg/h containing 23.5 wt % acetone and 76.5 wt % water is being extracted in a countercurrent….

Determine the break-point time, the fraction of total capacity used up to the break point, the length of the unused bed, and the saturation loading capacity of the solid.

Drying of Nitrogen and Scale-Up of a Column. Using molecular sieves, water vapor was removed from nitrogen gas in a packed bed (C1) at 28.3°C. The column height was 0.268….