Excel AVERAGE

OQ VI t ENACL Good(R) Good(R) Moderate Good Excellent Average... 

In this exercise, we have learned to calculate a mean, using both the built-in Excel AVERAGE function and a formula of our own design. In Chapter 6, we will use STDEV and other functions to complete our analysis of the data from the gravimetric determination of chloride that we began in Chapter 2. You may now close Excel by typing File/Exit or proceed to Chapter 6 to continue with the spreadsheet exercises. 

How Do I... Quote a mean and sample standard deviation of data What to Do in Excel =AVERAGE (range) =STDE M [range) where the range is a list of cells that contain the data, e.g., A1 A20, B1 H1... 

This scheme assumes that the density of all hair fibers is the same. It requires a minimum of manipulations and is an excellent averaging technique for dry state dimensions of hair fibers. Cross-sectional area and volume estimates for circular and elliptical fibers should be relatively accurate, as well as diameter and radius for round fibers. This method does not provide an indication of ellipticity but provides an average diameter with respect to length as well as to cross section (average diameter, not maximum or minimum diameter). The deviation of fiber diameter with increasing ellipticity is described in Table 8-9. 

This method, like the linear density method, is an excellent averaging technique and offers time advantages over the microscopic methods. 

Green Strength Excellent Excellent Excellent Excellent Average... 

Power density Good Excellent Average Excellent... 

On leaving the column, the components enter a plasma functioning in identical manner to that described in article 2.2.6.3. All the atoms present emit their own specific emission spectra and can be detected and quantified. The sensitivity is excellent for carbon, hydrogen, and sulfur and average for nitrogen and oxygen. 

Specific Surface. The total surface area of 1 g of powder measured ia cm /g is called its specific surface. The specific surface area is an excellent iadicator for the conditions under which a reaction is initiated and also for the rate of the reaction. It correlates in general with the average particle size. The great difference in surface area between 6-p.m reduced iron powder and 7-p.m carbonyl iron powder (Table 3) cannot be explained in terms of particle size, but mainly by the difference between the very inregular-shaped reduced and the spherical carbonyl iron powders. 

Typically, for single-suction pumps, suction-specific speed above 11,000 is considered excellent. Below 7000 is poor and 7000-9000 is of an average design. Similarly, for double-suction pumps, suction-specific speed above 14,000 is considered excellent, below 7000 is poor, and 9000-11,000 is average. 

One of the principal reasons for failure due to reaction with the service environment is the relatively complex nature of the reactions involved. Y"et, in spite of all the complex corrosion jargon, whether a metal corrodes depends on the simple elec trochemical cell set up by the environment. This might give the erroneous impression that it is possible to calculate such things as the corrosion rate of a car fender in the spring mush of salted city streets. Dr. M. Pourbaix has done some excellent work in the application of thermodynamics to corrosion, but this cannot yet be applied direc tly to the average complex situation. 

The three-dimensional, quantitative nature of STM and SFM data permit in-depth statistical analysis of the surface that can include contributions from features 10 nm across or smaller. By contrast, optical and stylus profilometers average over areas a few hundred A across at best, and more typically a pm. Vertical resolution for SFM / STM is sub-A, better than that of other profilometers. STM and SFM are excellent high-resolution profilometers. 

Average moleeular weight development can be measured directly through GPC or SEC, as we mentioned earlier. These measurements have their own problems, but can be very useful when properly tested and interpreted. They provide an excellent basis for predicting PF performance. They can also give an overview of PF eondensation kinetics and even some information about polymer shapes. However, they do not provide detailed information on the chemical structure of the polymer. Such information is required to propose reasonable mechanisms. C-... 

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