A grocer has sales of Rs. 3200, Rs. 3280, Rs. 3300 and Rs. 3400 in 4 consecutive months. At least how much should the sale be in the 5th month to get an average sale of Rs. 3300?

1. A

   Rs. 3340

2. B

   Rs. 3320

3. C

   Rs. 3360

4. D

   Rs. 3370

Appeared in: DSSSB -28 August 2019 (Shift-2)

Explanation

• The target average sale over 5 months is Rs. 3300.
• The total required sale is the average multiplied by the number of months: 5 × 3300 = Rs. 16,500.
• The sum of sales for the first four months is 3200 + 3280 + 3300 + 3400 = Rs. 13,180.
• To find the required sale for the fifth month, subtract the four-month total from the required five-month total: 16,500 - 13,180 = Rs. 3,320.

Why Other Options Were Wrong

• Option A: This value is higher than the minimum required amount. While a sale of Rs. 3340 would result in an average greater than Rs. 3300, the question asks for the minimum ('at least') amount needed.
• Option C: This is also higher than the calculated minimum. It's a possible sale amount but not the least amount required to meet the goal.
• Option D: This value is significantly higher than the minimum required sale of Rs. 3320.

Related Visual

Clinical Relevance

• Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Calculating a missing value to achieve a target arithmetic mean (average) as background academic context rather than a clinical decision trigger.
• Understanding averages is a fundamental mathematical skill used in various daily and professional contexts, including calculating budgets or analyzing performance data.
• In a clinical setting, nurses use averages to track trends in vital signs (like average heart rate over an hour) or calculate average fluid intake/output over a shift.
• This skill is also crucial for medication dosage calculations, especially when titrating drips based on patient response over time.

How to Approach the Question

• First, identify the goal: find the value of the 5th data point to achieve a specific average for all 5 data points.
• Use the formula for the total sum: Total Sum = Target Average × Number of Data Points.
• Calculate the required total sum for the 5 months: 3300 × 5 = 16,500.
• Next, calculate the sum of the existing data points (the sales from the first 4 months).
• Subtract the sum of the known data from the required total sum to find the value of the missing data point.
• Compare the result with the given options to find the correct answer.

Concept Tested & Keywords

• Concept Tested: Calculating a missing value to achieve a target arithmetic mean (average).
• Stem keywords: grocer, sales, consecutive months, average sale
• Lead-in keywords: at least how much
• Negative lead-in flag: false

Question ID

QCHI5mXG1L0i930z_aEST

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