Aconsumer group was interested in comparing the operating time of cordless toothbrushes manufactured by two different companies. group members took a random sample of 18 toothbrushes from company a and 15 from company b. each was charged overnight and the number of hours of use before needing to be recharged was recorded. company a toothbrushes operated for an average of 119.7 hours with a standard deviation of 1.74 hours; company b toothbrushes operated for an average of 120.6 hours with a standard deviation of 1.72 hours.1. which of the following statements is true? a. this is a one tailed test of two dependent samplesb. this is a two tailed test of two independent samplesc. this is a one tailed test of two independent samplesd. these samples are matchede. none of the above