Answer:80
Assume the number to be 400 for instance,
10% of 400 increased = 400 + ( 10/100 × 400 )
= 400 + 40 = 440
The resulting number decreased by its 10% = 400 - (10/100 × 400)
= 400 - 40 = 360
Now, net decrease = 440 - 360 = 80
Look the lesson up online. Sometimes there is an answer key
Answer:
yes
Step-by-step explanation:
All you need to do for this really is use a calculator and confirm answers are correct and they are. After that you need to show your work to prove the answers are correct.
Answer:C. (77.29, 85.71)
Step-by-step explanation:
We want to determine a 95% confidence interval for the mean test score of randomly selected students.
Number of sample, n = 25
Mean, u = 81.5
Standard deviation, s = 10.2
For a confidence level of 95%, the corresponding z value is 1.96. This is determined from the normal distribution table.
We will apply the formula
Confidence interval
= mean +/- z ×standard deviation/√n
It becomes
81.5 +/- 1.96 × 10.2/√25
= 81.5 +/- 1.96 × 2.04
= 81.5 +/- 3.9984
The lower end of the confidence interval is 81.5 - 3.9984 =77.5016
The upper end of the confidence interval is 81.5 + 3.9984 =85.4984
Therefore, the correct option is
C. (77.29, 85.71)
Answer:
false
Step-by-step explanation:
