Two different groups in a statistics class are conducting a survey to estimate the mean number of units students at their college are enrolled in. the population mean and standard deviation are unknown. the sample from the first group survey has 49 data values. the sample from the second group survey has 81 data values. for each sample, the groups construct a 90% confidence interval to estimate the population mean. which confidence interval will have greater precision (smaller width) for estimating the population mean?

Answer: d. 39 cmin the diagram, the approximate length of the minor arc de is 39 centimetres.step-by-step explanation: the formula for the length of an arc in a circle is as displayed below.let the length of the minor arc de = xx = 2( pi )r × angle of sector / 360°from this, we will substitute the values given from the problem into the formula to obtain the length of the minor arc de.x = 2( pi )r × angle of sector / 360°r = radius = 25cmpi as an approximate value = 3.14angle of sector = 120°x = 2( 3.14 )( 25 ) × 120° / 360°x = 157 × 1 / 4x = 39.25x = 39 ( rounded to the nearest whole number as an approximate value )