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barcode font reporting services Tests of Hypotheses and Significance in Software
CHAPTER 7 Tests of Hypotheses and Significance Decode QRCode In None Using Barcode Control SDK for Software Control to generate, create, read, scan barcode image in Software applications. QR Generation In None Using Barcode generation for Software Control to generate, create QR Code image in Software applications. (b) If the level of significance is 0.01, the z1 value in Fig. 75 is (1) Reject H0 if Z is less than 2.33. Quick Response Code Scanner In None Using Barcode scanner for Software Control to read, scan read, scan image in Software applications. QR Code Encoder In Visual C# Using Barcode creator for VS .NET Control to generate, create QR image in .NET framework applications. 2.33. Hence we adopt the decision rule: QRCode Generator In .NET Using Barcode drawer for ASP.NET Control to generate, create Quick Response Code image in ASP.NET applications. QR Code JIS X 0510 Generation In .NET Using Barcode creator for VS .NET Control to generate, create QRCode image in .NET applications. (2) Accept H0 (or withhold any decision) otherwise. Since, as in Problem 7.7(a), the z score is 2.50, which is less than 2.33, we reject H0 at a 0.01 level of significance. Note that this decision is not the same as that reached in Problem 7.7(b) using a twotailed test. It follows that decisions concerning a given hypothesis H0 based on onetailed and twotailed tests are not always in agreement. This is, of course, to be expected since we are testing H0 against a different alternative in each case. (c) The P value of the test is P(Z 1570) 0.0062, which is the probability that a mean lifetime of less than 1570 hours would occur by chance if H0 were true. Quick Response Code Generation In Visual Basic .NET Using Barcode creation for VS .NET Control to generate, create QR Code image in .NET framework applications. Code128 Creation In None Using Barcode drawer for Software Control to generate, create Code128 image in Software applications. 7.9. The breaking strengths of cables produced by a manufacturer have mean 1800 lb and standard deviation 100 lb. By a new technique in the manufacturing process it is claimed that the breaking strength can be increased. To test this claim, a sample of 50 cables is tested, and it is found that the mean breaking strength is 1850 lb. (a) Can we support the claim at a 0.01 level of significance (b) What is the P value of the test Encode Code 39 In None Using Barcode creation for Software Control to generate, create Code39 image in Software applications. GTIN  12 Encoder In None Using Barcode printer for Software Control to generate, create GS1  12 image in Software applications. (a) We have to decide between the two hypotheses H0: m H1: u 1800 lb, and there is really no change in breaking strength 1800 lb, and there is a change in breaking strength Barcode Generator In None Using Barcode creator for Software Control to generate, create barcode image in Software applications. UCC128 Printer In None Using Barcode creator for Software Control to generate, create EAN128 image in Software applications. A onetailed test should be used here (see Fig. 74). At a 0.01 level of significance the decision rule is: (1) If the z score observed is greater than 2.33, the results are significant at the 0.01 level and H0 is rejected. (2) Otherwise H0 is accepted (or the decision is withheld). Under the hypothesis that H0 is true, we find Z # X m s> !n 1850 1800 100> !50 3.55 ANSI/AIM I2/5 Maker In None Using Barcode generation for Software Control to generate, create I2/5 image in Software applications. Generate GS1 DataBar Truncated In Java Using Barcode printer for Java Control to generate, create GS1 DataBar image in Java applications. which is greater than 2.33. Hence we conclude that the results are highly significant and the claim should be supported. (b) The P value of the test is P(Z 3.55) 0.0002, which is the probability that a mean breaking strength of 1850 lb or more would occur by chance if H0 were true. Make Barcode In .NET Framework Using Barcode generation for VS .NET Control to generate, create barcode image in VS .NET applications. UCC  12 Drawer In None Using Barcode maker for Word Control to generate, create UPC Symbol image in Office Word applications. Tests involving differences of means and proportions 7.10. An examination was given to two classes consisting of 40 and 50 students, respectively. In the first class the mean grade was 74 with a standard deviation of 8, while in the second class the mean grade was 78 with a standard deviation of 7. Is there a significant difference between the performance of the two classes at a level of significance of (a) 0.05, (b) 0.01 (c) What is the P value of the test Paint EAN 128 In ObjectiveC Using Barcode generation for iPhone Control to generate, create EAN 128 image in iPhone applications. Encode Bar Code In Visual Basic .NET Using Barcode printer for .NET Control to generate, create bar code image in VS .NET applications. Suppose the two classes come from two populations having the respective means m1 and m2. Then we have to decide between the hypotheses H0: m1 m2, and the difference is merely due to chance Code128 Drawer In None Using Barcode creation for Word Control to generate, create USS Code 128 image in Microsoft Word applications. Encoding Matrix Barcode In Visual C# Using Barcode printer for .NET framework Control to generate, create Matrix 2D Barcode image in VS .NET applications. H1: m1 2 m2, and there is a significant difference between classes Under the hypothesis H0, both classes come from the same population. The mean and standard deviation of the difference in means are given by mX1 s2 1 A n1
s2 2 n2
82 40 A 72 50 where we have used the sample standard deviations as estimates of s1 and s2.
CHAPTER 7 Tests of Hypotheses and Significance
# # X1 X2 sX1 X2
Then
74 78 1.606 (a) For a twotailed test, the results are significant at a 0.05 level if Z lies outside the range 1.96 to 1.96. Hence we conclude that at a 0.05 level there is a significant difference in performance of the two classes and that the second class is probably better. (b) For a twotailed test the results are significant at a 0.01 level if Z lies outside the range 2.58 and 2.58. Hence we conclude that at a 0.01 level there is no significant difference between the classes. Since the results are significant at the 0.05 level but not at the 0.01 level, we conclude that the results are probably significant, according to the terminology used at the end of Problem 7.5. (c) The P value of the twotailed test is P(Z 2.49) P(Z 2.49) that the observed statistics would occur in the same population. 0.0128, which is the probability 7.11. The mean height of 50 male students who showed aboveaverage participation in college athletics was 68.2 inches with a standard deviation of 2.5 inches, while 50 male students who showed no interest in such participation had a mean height of 67.5 inches with a standard deviation of 2.8 inches. (a) Test the hypothesis that male students who participate in college athletics are taller than other male students. (b) What is the P value of the test (a) We must decide between the hypotheses H0: m1 H1: m1 m2, and there is no difference between the mean heights m2, and mean height of first group is greater than that of second group

