The chart indicates the variation was 3°45'E...

Question 1 of 2707066636ee928f7522a1c51931d

The chart indicates the variation was 3°45'E in 1988, and the annual change is increasing 6'. If you use the chart in 1991 how much variation should you apply?

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Question 1 of 27070

Q

The chart indicates the variation was 3°45'E in 1988, and the annual change is increasing 6'. If you use the chart in 1991 how much variation should you apply?

🔍 Key Concepts

• How to calculate the total number of years between the chart’s reference year and the year of use • Converting annual change in minutes (') to total change over several years • How to correctly apply an easterly variation that is increasing over time

💭 Think About

• From 1988 to 1991, how many full years of annual change have occurred, and what is the total change in minutes? • What does an increasing easterly variation do to the original easterly value: does it get larger or smaller? • After adding or subtracting the total change, what is the new variation in degrees and minutes, and which answer choice is closest?

✅ Before You Answer

• Confirm the time span: 1991 - 1988 = ? years • Multiply the annual change (6' per year) by the number of years to find the total change in minutes • Make sure you applied the change in the correct direction for an easterly variation increasing before comparing with the answer choices