Solution: To find the z-score, we use the formula: z = (x - mean) / standard deviation. Plugging in the values, we get: z = (60,000 - 50,000) / 5,000 = 2 The z-score for an employee who earns $60,000 is 2, which means that this employee's salary is 2 standard deviations above the average salary of the company. Problem 3: Apr 14, 2020 · Question: Find the Z critical value for a left-tailed test with a significance level of 0.05. Answer: invNorm(.05, 0, 1) = -1.6449. Interpretation: If the test statistic of the test is less than -1.6449, then the results of the test are statistically significant at α = 0.05. Example 2: Z Critical Value for a Right-Tailed Test The Z-scores of ± 1.96 are the critical Z-scores for a 95% confidence interval. Table 1. Common critical values (Z-scores). Construction of a confidence interval about μ when σ is known: (critical value) (margin of error) (point estimate ± margin of error) Nov 28, 2022 · For instance, if your confidence level is $99\%$, the confidence coefficient would be $.99$. In broad, the greater the coefficient, the more confident you are that your results are precise. For instance, a $.99$ coefficient is more precise than a coefficient of $.89$. Q 8.2.1. Among various ethnic groups, the standard deviation of heights is known to be approximately three inches. We wish to construct a 95% confidence interval for the mean height of male Swedes. Forty-eight male Swedes are surveyed. The sample mean is 71 inches. The sample standard deviation is 2.8 inches. ˉx. x ¯. =________. 7. Determine the critical value for a 95% level of confidence (p<0.05). If you are using the 95% confidence level, for a 2-tailed test you need a z below -1.96 or above 1.96 before you say the difference is significant. For a 1-tailed test, you need a z greater than 1.65. The critical value of z for this test will therefore be 1.65. 8. .

critical z score for 99 confidence interval