/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 7 The first three members of the s... [FREE SOLUTION] | 91Ó°ÊÓ

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The first three members of the stilt-walking relay team finished their laps of the race with a mean time of 53 seconds per lap. What mean time for the next two members will give an overall team mean of 50 seconds per lap? (Th)

Short Answer

Expert verified
The next two members need a mean time of 45.5 seconds per lap.

Step by step solution

01

Understand the Problem

We know that the first three members of the team take an average of 53 seconds per lap. We need to find the mean lap time for the next two members so that the overall average lap time for the team of five members is 50 seconds.
02

Calculate Total Time for First Three Members

Since the mean time for the first three members is 53 seconds per lap, the total time taken by them is \(3 \times 53 = 159\) seconds.
03

Set Up the Equation for the Overall Team Mean

The total time for all five members should lead to a mean of 50 seconds per lap. So, for 5 members, the total time should be \(5 \times 50 = 250\) seconds.
04

Find the Total Time Needed for Last Two Members

To find out the time for the last two members, subtract the total time taken by the first three members from the desired total time: \(250 - 159 = 91\) seconds.
05

Calculate Mean Time for Last Two Members

Divide the total time needed for the last two members by 2 to find their mean time: \(91 / 2 = 45.5\) seconds.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Understanding Mean Calculation
When dealing with mean calculation, it helps to first understand what 'mean' actually means. The mean is essentially the average of a set of numbers.
To find this, you simply add up all the numbers and then divide by the total count of numbers. In this problem, we initially had three team members whose combined lap time was 159 seconds, which results in a mean lap time of 53 seconds for them. By setting the overall mean desired at 50 seconds for all five members, we then calculate backwards to see what the remaining two members' mean time would need to be. Here’s a simple walkthrough:
  • First three team members: total time, 159 seconds; mean time per person, 53 seconds.
  • Overall desired mean for all five: 50 seconds per person.
  • Adjust the total time calculation to achieve this mean with five participants.
This backward calculation is key when you have specific mean requirements and partial initial data.
Enhancing Problem Solving Skills
Developing effective problem solving skills starts with breaking down a problem into manageable steps. In this scenario, we identified the initial situation (the mean time of the first three members) and the desired outcome (an overall team mean of 50 seconds).
We then used logical reasoning to find what's missing - in this case, the mean time needed for the remaining two team members. Here are some vital strategies to strengthen your problem solving skills:
  • Identify what you know and what you need to find out. This clarifies the problem's scope.
  • Work step-by-step to avoid skipping crucial elements.
  • Check your work as you progress, ensuring each part builds on the last correctly.
By practicing these methods, you create a road map that leads you to a successful solution. Such structured approaches are universally applicable, from math problems to real-world challenges.
Mastering Equation Setup
Setting up equations correctly is crucial for resolving mathematical problems. In this case, we used an equation to represent the overall mean lap time for the stilt-walking relay team.
Here's how you can set it up and solve such equations efficiently. Understanding the problem's structure helps in forming accurate equations:
  • Always define what each element of the equation represents—here, the 250 seconds is the result of multiplying the desired mean (50 seconds) by five runners.
  • Calculate known variables first; we calculated the time the first three runners took (159 seconds).
  • Use the equation to find unknowns—in our task, this was the combined time for the last two runners (250 - 159 = 91 seconds).
Ultimately, forming equations involves translating what's happening in words into mathematical terms. Once you become familiar with setting up and solving equations, you can tackle a wide array of problems with confidence.

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Most popular questions from this chapter

Check your vocabulary by answering these questions. a. How does the term quartile relate to how data values are grouped when using a five-number summary? (a) b. What is the name for the difference between the minimum and maximum values in a five-number summary? (a) c. What is the name for the difference between the third quartile and first quartile in a five-number summary? d. How are outliers of a data set related to the whiskers of its box plot?

APPLICATION A string and meterstick were passed around a class, and each student measured the length of the string with a precision of \(0.1 \mathrm{~cm}\). Here are their results: \(\begin{array}{rrrrrrrrrrr}126.5 & 124.2 & 124.8 & 125.7 & 123.3 & 124.5 & 125.4 & 125.5 & 123.7 & 123.8 & 126.4 \\ 126.0 & 124.6 & 123.3 & 124.7 & 125.4 & 126.1 & 123.8 & 125.7 & 125.2 & 126.0 & 125.6\end{array}\) a. What does the true length of the string probably equal? (a) b. Why are there so many different values? c. Sometimes you see a measurement like \(47.3 \pm 0.2 \mathrm{~cm}\). What do you think the " \(\pm 0.2\) " means? (a) d. Create a measurement like the one shown in \(11 \mathrm{c}\), which has an accuracy or error component, to describe the length of the string. (a)

For each description, invent a seven-value data set such that all the values in the set are less than 10 and meet the conditions. a. The box plot represents data with a median that is not inside the box. (a) b. The box plot represents data with an interquartile range of zero. c. The box plot represents data with one outlier on the left. d. The box plot has no right whisker.

Is \([A]+[B]\) equal to \([B]+[A]\) ? Do you think this result is always true for matrix addition? Explain.

Find the mean, median, and mode for each data set. a. \(\\{1,5,7,3,5,9,6,8,10\\}\) (ai) b. \(\\{6,1,3,9,2,7,3,4,8,8\\}\) c. \(\\{12,6,11,7,18,5,2,21\\}\) (a) d. \(\\{10,10,20,20,20,25\\}\)

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