Question
upstudy study bank question image url

After entering the test scores from her Statistics class of 33 students, the instructor calculated the mean, median, IQR and standard deviation of the tes scores. Upon checking, she discovered that she had entered the top score as 85 , but it should have been 95 . a) When she corrects this score, how will the mean and median be affected? b) What effect will correcting the error have on the IQR and the standard deviation? a) Determine how the mean will be affected. Select the correct choice below and, if necessary, fill in the answer box within your choice. A. The mean will increase by \( \square \) points. (Round to two decimal places as needed.) B. The mean will decrease by \( \square \) points. (Round to two decimal places as needed.) C. The mean will not change. D. It is impossible to determine how the mean will change.

Ask by Nichols Gough. in the United States
Jan 23,2025

Real Tutor Solution

Tutor-Verified Answer

Answer

The mean will increase by approximately 0.30 points.

Solution

To determine how the mean will be affected when the instructor corrects the top score from 85 to 95, we need to calculate the new mean after the correction. Given: - Original top score: 85 - Corrected top score: 95 - Number of students: 33 Let's denote the sum of the original scores as \( S \) and the sum of the corrected scores as \( S' \). The original mean is calculated as: \[ \text{Original Mean} = \frac{S}{33} \] After correcting the top score, the new sum of scores is: \[ S' = S - 85 + 95 \] The new mean is calculated as: \[ \text{New Mean} = \frac{S'}{33} \] Now, let's calculate the difference between the new mean and the original mean to determine how the mean will be affected. Calculate the value by following steps: - step0: Calculate: \(\frac{\left(95-85\right)}{33}\) - step1: Remove the parentheses: \(\frac{95-85}{33}\) - step2: Subtract the numbers: \(\frac{10}{33}\) The difference between the new mean and the original mean is \( \frac{10}{33} \) or approximately 0.30 points. Therefore, the mean will increase by approximately 0.30 points when the instructor corrects the top score from 85 to 95.

Reviewed and approved by the UpStudy tutoring team

error msg
Explain
Simplify this solution

Extra Insights

When that top score goes from 85 to 95, the sum of all the test scores will increase, thus raising the mean. To find out how many points it increases, you can use the formula for the mean, which is the total sum of scores divided by the number of students. In this case, with an increase of 10 points (the difference between 95 and 85) across 33 students, the mean will increase by \( \frac{10}{33} \), which is approximately \( 0.30 \) points. The median, on the other hand, is determined by the middle score in a sorted list. Since the score of 95 will likely change the placement of students below the median, you may find the median also increases, especially if the median was around or below 85. If the median score doesn’t include the top score, it may not change, but if it’s at or near that value, it could boost up, shifting the median score by at least a point or two, depending on the distribution of the other scores. So, in conclusion: A. The mean will increase by \( 0.30 \) points.

Related Questions

Latest Statistics Questions

Try Premium now!
Try Premium and ask Thoth AI unlimited math questions now!
Maybe later Go Premium
Study can be a real struggle
Why not UpStudy it?
Select your plan below
Premium

You can enjoy

Start now
  • Step-by-step explanations
  • 24/7 expert live tutors
  • Unlimited number of questions
  • No interruptions
  • Full access to Answer and Solution
  • Full Access to PDF Chat, UpStudy Chat, Browsing Chat
Basic

Totally free but limited

  • Limited Solution
Welcome to UpStudy!
Please sign in to continue the Thoth AI Chat journey
Continue with Email
Or continue with
By clicking “Sign in”, you agree to our Terms of Use & Privacy Policy