A scientist counted the number of seeds produced by four plants as 55,30,75,40. The standard deviation of the number of seeds is approximately 19.6. 383.3 . 30. 17.

To find the standard deviation of the number of seeds produced by the four plants, we can follow these steps:<br /><br />1. Calculate the mean (average) of the data set.<br />2. Subtract the mean from each data point and square the result.<br />3. Sum up the squared results.<br />4. Divide the sum by the number of data points (for a sample standard deviation, divide by n-1).<br />5. Take the square root of the result.<br /><br />Let's calculate the standard deviation step by step:<br /><br />1. Mean: (55 + 30 + 75 + 40) / 4 = 50<br />2. Subtract the mean from each data point and square the result:<br /> - (55 - 50)^2 = 25<br /> - (30 - 50)^2 = 400<br /> - (75 - 50)^2 = 625<br /> - (40 - 50)^2 = 100<br />3. Sum up the squared results: 25 + 400 + 625 + 100 = 1150<br />4. Divide the sum by the number of data points (for a sample standard deviation, divide by 4-1 = 3): 1150 / 3 ≈ 383.3<br />5. Take the square root of the result: √383.3 ≈ 19.6<br /><br />Therefore, the standard deviation of the number of seeds produced by the four plants is approximately 19.6.