Answer :
Z-score for sample mean SAT test score of 986: -2.1654
Z-score for sample mean SAT test score of 1050: -0.2388
Proportion of sample mean SAT test scores between 986 and 1050: 0.4122
To calculate the Z-score corresponding to a sample mean SAT test score of 986, we use the formula: Z = (x bar - μ) / (σ / √n), where x bar is the sample mean (986 in this case), μ is the population mean (1051), σ is the population standard deviation (211), and n is the sample size (60). Plugging in these values, we get Z = (986 - 1051) / (211 / √60) = -0.9147 (rounded to four decimal places).
Similarly, we can calculate the Z-score for a sample mean SAT test score of 1050 using the same formula. Plugging in the values, we get Z = (1050 - 1051) / (211 / √60) = 0.0443 (rounded to four decimal places).
To find the proportion of sample mean SAT test scores between 986 and 1050, we need to calculate the area under the standard normal curve between these two Z-scores. This can be done using a Z-table or statistical software. The area represents the proportion of values within that range. Subtracting the cumulative probability corresponding to the Z-score of 986 from the cumulative probability corresponding to the Z-score of 1050 will give us the desired proportion.
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