Answer:
Step-by-step explanation:
Select the correct answer from each drop-down menu.
We solve using z score formula
z-score is z = (x-μ)/σ, where x is the raw score, μ is the population mean, and σ is the population standard deviation.
The average time taken to complete a test follows normal probability distribution with a mean of 70 minutes and a standard deviation of 25 minutes.
a) The probability of a randomly selected student completing the test in 45 minutes or less is approximately equal to %.
z = 45 - 70/25
b) The probability of a randomly selected student completing the test in 95 minutes is %.
z = 95 - 70/25
The answer to the question
Answer:
42%
Step-by-step explanation:
To find the percent of decrease first find the difference between 32.25 and 18.70.
32.25 - 18.70 = 13.55
Now divide this number by the original number, in this case 32.25, and then multiply the answer you get by 100.
13.55 / 32.25 = 0.42
Multiply this number by 100 to get the percentage.
0.42 * 100 = 42