Statistics :

19 1 point Ms. Basher is the owner of a new restaurant. She wants to figure out how much the number of customers fluctuate, so she can determine the number of new staff she needs to hire. To do so, Ms. Basher measures the number of customers in her restaurant twice a day (breakfast and dinner service) for a week (7 days). Ms. Basher finds that the mean number of customers is 140. The sum of the squared deviation scores (SS) is 700. What is the variance? O 53.8 O 116.67 5 O 501 point Standard IQ scores have a mean of 100 and a standard deviation of 15. When Braden was in 9th grade, his IQ was measured to be 60. When he was in 11th grade, it was measured to be 80. His psychologist wants to express Braden's IQ in terms of a z-score. To do so, the psychologist takes the average of the two scores (the one from 9th grade and the one from 11th grade) and then computes the z-score. What will the z-score of Braden's IQ be? C - 2 There's not enough information to solve this problem. 2 O O11 1 point Coach Johnson uses the 40-yard dash to screen for football tryouts. He only permits students with extremely fast 40-yard dash times to take part in the final round of tryouts He considers any score that is more than 2 SD from the mean to be extremely fast. He knows that mean performance time on the 40-yard dash is 5.5 seconds and that the SD is 0.5 seconds. How quickly do students need to complete the 40-yard dash to be permitted to take part in the final round of tryouts? Greater than 6 seconds Less than 5 seconds Greater than 5.5 seconds O Less than 4.5 seconds 12 1 point The variance is... always a negative number never at the same scale of units as the data sometimes at the same scale of units as the data O the square root of the standard deviation 13 1 point Michael's z-score for his last exam was a -2. He knows the mean for the exam is 78, and the SD is 7. What is Michael's raw score for the exam? -14 64 92 O 58