Question

A cellular phone company monitors monthly phone usage. The following data represent the monthly phone use in minutes of one particular customer for the past 20 months. Use the given data to answer parts (a) and (b). 339 359 470 411 379 365 552 517 554 328 349 401 417 489372 466514 314 474 437 la) Determine the standard deviation and interquartile range of the data (Round to two decimal places as needed) IQR -(Type an integer or a decimal) (b) Suppose the month in which the customer used 339 minutes was not actually that customer's phone. That particular month the customer did not use their phone at all, so 0 minutes were used. How does changing the observation from 330 to affect the standard deviation and interquartile range? What property does this illustrate? The standard deviation and the interquartile range What property does this llustrate? Choose the correct answer below O Resistance O Dispersion Weighted Mean mpir Rule

Answer 1

sol. Given data , dal! From the given data - 0557 339+ 437 Moanlã) = EX 20 20 497.85 a) Standard deviation (s): [(xi -j? n-1 (339-497.85 ) + +(437-427.85) S = 20-1 5273.6078947368 72.619610951429 79.69 1 our sorted data is :-(328, 339,344, 349,359,372, 379, 385 401,411,417,437, 466, 470, 474,489,514,6517, 552 554) The first quartell (Qe) 365.5 The third e quartile (63) = L181.5 I QR = Q3 - Q1 = 481.5 - 36 5. 5 116 = Ay (b ) increase and the I QR will The standard deviation romans the same. y Resistance.