The normal distribution shown below was used to model the results of the PLANEA test for a certain year. The mean of the distribution is 76.5 and the standard deviation is 5.2 points. If you look at the figure, three values are missing from the x-axis. The middle value goes below the highest part of the curve, and the left and right values are the same distance (equidistant) from the value in the middle. Use the empirical rule to choose the value that best represents the percentage of the area under the curve that is highlighted. Also write the missing values. Percentage of total area shaded: (Choose one) v 600 65 70 75 I 80 85 90 95 Test score

A standardized exam's scores are normally distributed. In a recent year, the mean test score was 1522 and the standard deviation was 311. The test scores of four students selected at random are 1950, 1260, 2190, and 1410. Find the z-scores that correspond to each value and determine whether any of the values are unusual. The z-score for 1950 is. (Round to two decimal places as needed.)

A standardized exam's scores are normally distributed. In a recent year, the mean test score was 1539 and the standard deviation was 315. The test scores of four students selected at random are 1940, 1290, 2240, and 1420. Find the z-scores that correspond to each value and determine whether any of the values are unusual. The z-score for 1940 is. (Round to two decimal places as needed.) The Z-score for 1290 is. (Round to two decimal places as needed.) The Z-score for 2240 is. (Round to two decimal places as needed.) The Z-score for 1420 is. (Round to two decimal places as needed.) Which values, if any, are unusual? Select the correct choice below and, if necessary, fill in the answer box within your choice. OA. The unusual value(s) is/are. CD (Use a comma to separate answers as needed.) OB. None of the values are unusual.

A manufacturer of light bulbs finds that one light bulb model has a mean life span of 1025 h with a standard deviation of 83 h.Find the z-scores for lightbulbs which last 850 and 900 h. (Round your answers to two decimal places.) 850 h: z = 900 h: z =

A distribution of values is normal with a mean of 246.2 and a standard deviation of 99.5. Find P78, which is the score separating the bottom 78% from the top 22%. P78 Enter your answer as a number accurate to 4 decimal places.