A researcher examines 8 sedimentary samples for nitrate concentration. The mean nitrate concentration for the sample data is 0.688 cc/cubic meter with a standard deviation of 0.0701. Determine the 95% confidence interval for the population mean nitrate concentration. Assume the population is approximately normal. Step 1 of 2: Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.

solution:

as, mean is defined as sum of all the observations divided by total number of observations.

and , median is mid value of the data whether arranged in ascending order or descending order.

consider, roadsters:

2,3,4,5,6,7,8,9

mean =

also, median= , because number of observations is even, so median is mean of two mid values.

now, coming to bandits

2,3,4,5,6

mean =  

median = 4, as number of observations is odd.

so, roadsters has greater median as well mean than bandits.

→option a is true about the repairs performed on 2 types of cars:

bandits have lower median and mean than roadsters.

answer: for each 3 girls there is 2 boys . 3: 2

hope this ! (:   mark me as brainliest if you can

175

step-by-step explanation:

2 inches x 10 miles = 200 miles - 3 inches = 175