The highway safety department wants to study the driving habits of individuals. a sample of 38 cars traveling on a particular stretch of highway revealed an average speed of 70.9 miles per hour with a standard deviation of 7.8 miles per hour. round to 4 decimal places. 1.calculate a 95% confidence interval for the true mean speed of all cars on this particular stretch of highway.

answer: 140

step-by-step explanation:

so just add all then it will be your answer but i am not pretty sur eif it is but hope this i am here to people

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.

14.3

step-by-step explanation:

add all the numbers together.

9 + 12 + 15 + 16 + 17 + 17 = 86

now, divide 86 by how many numbers we have: 6.

86 / 6 = 14.3