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# Help with Sampling Homework? watch

1. I'm having trouble answering this question.

Toby is investigating the variation in daily total sunshine for Heathrow in May, June and July 1987. He used the large data set to select a sample size 30 from the May, June and July data for 1987. Toby selected the first value using a random number from 1 to 4 and then selected every third value after that.

From your knowledge of the large data set, explain why this process will not generate a sample of size 30.

I think that it might be as some of the reluts are labelled N/A but wouldn't he want to include these in his sample?

Thanks for any help
2. I assume the following.

If his random number is one then he takes days 1,4,7.... etc. This takes him to day 88 which does not cover the full 91 day period, I might be wrong though.
3. (Original post by Andrew97)
I assume the following.

If his random number is one then he takes days 1,4,7.... etc. This takes him to day 88 which does not cover the full 91 day period, I might be wrong though.
That's what I'm probably going to put

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Updated: February 4, 2018
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