Earth travels in an approximately circular orbit around the sun. the average radius of earth's orbit around the sun is 9.3 times 10 superscript 7 miles. earth takes one year, or 365 days, to complete one orbit.
a. use the formula for the circumference of the circle to determine the distance, upper l, the earth travels in one year. express your answers in scientific notation.
l=a * 10^n
b. how many hours, h are in one year?
c. speed is distance divided by time. find the orbital speed, v, of earth in miles per hour.
v= ? miles per hour

Atechnician compares repair costs for two types of microwave ovens (type i and type ii). he believes that the repair cost for type i ovens is greater than the repair cost for type ii ovens. a sample of 6767 type i ovens has a mean repair cost of $79.79$⁢79.79. the population standard deviation for the repair of type i ovens is known to be $19.18$⁢19.18. a sample of 5555 type ii ovens has a mean repair cost of $75.24$⁢75.24. the population standard deviation for the repair of type ii ovens is known to be $21.40$⁢21.40. conduct a hypothesis test of the technician's claim at the 0.050.05 level of significance. let μ1μ1 be the true mean repair cost for type i ovens and μ2μ2 be the true mean repair cost for type ii ovens. step 2 of 4 : compute the value of the test statistic. round your answer to two decimal places.