An inspector inspects large truckloads of potatoes to determine the proportion p in the shipment with major defects prior to using the potatoes to make potato chips. Unless there is clear evidence that this proportion, p, is less than 0.10, he will reject the shipment. He will test the hypotheses

H0: p = 0.10, Ha: p < 0.10.

He selects an SRS of 100 potatoes from the large number of potatoes on the truck. Suppose that six of the potatoes sampled are found to have major defects.

A 95% confidence interval for the true proportion of potatoes in the truck that have major defects is:

[Hint: you need to decide whether to use the large sample formula or the Plus-four method for confidence intervals]