Problem 2 (15 points). Usually the first thing to do after measurements and data
ID: 1867494 • Letter: P
Question
Problem 2 (15 points). Usually the first thing to do after measurements and data acquisition is to plot out the data graphically in some way so the central trend and certain patterns may be observed. Please answer the following five questions: 1) When the distribution of the number of occurrence of the signal's values per certain sample value interval is displayed, the plot is commonly called (a) a frequency spectrum; (b) a time history record; (c) a sample histogram; (d) a scattergram. The equal-width interval histograms are most often used to show both the frequency and distribution of occurrences. Its optimal interval width is typically based on interval used in sampling: (b) the maximum frequency in the signal sampled; (c) the ratio of the sampling duration over the sampling time interval; (d) the total sampling duration. 3) Two conditions are often checked when constructing a histogram, namely (a) the total number of samples is larger than 25 and the interval width is larger than the time interval; (b) the number of occurrence within each interval width is larger than 5 and the interval width is larger than the measurement uncertainty; (c) the sum of all numbers of occurrences equal sample number and the interval width is larger than the time interval; (d) the number of internal is less than 30 and the interval width is larger than the measurement uncertainty The statistical concept of degrees of freedom is defined as the number of recorded data N minus s to the total 4) the number of different and independent constraints c used in a statistical calculation: N-c. For computing the sample standard deviation or variance, the number of degrees of example, when computing the sample standard deviation o freedom is (a) N; (b) The normal probability density function describes well the measurement variabilities due to a very larger number of small random is usually far from being normally distributed because image brightness; (b) the number of pixels in an image is not insufficiently large; (c) the brightness of individual pixels in an image are spatially correlated and not randomly distributed; (d) the brightness interval width used in the histogram is incorrect. N-1; (c) N-2; (d) N/2 5) effects. However, the brightness histogram of a digital image a) there are no random noises in theExplanation / Answer
1) a sample histogram
because it is the distribution of number of occurance of signal value
2)the time interval used in sampling
3)b. the number of occurance with each interval equal to total number of occurance and the interval widh larger than time interval
4)N-2
5)the brightness width used in histogram is incorrect