Question

(CO6) If the population standard deviation of a increases without other changes, what is most likely to happen to the confidence interval?

narrows

widens

does not change

cannot determine

(CO6) A company making refrigerators strives for the internal temperature to have a mean of 37.5 degrees with a population standard deviation of 0.6 degrees, based on samples of 100. A sample of 100 refrigerators have an average temperature of 37.48 degrees. Are the refrigerators within the 90% confidence interval?

No, the temperature is outside the confidence interval of (37.40, 37.60)

No, the temperature is outside the confidence interval of (36.90, 38.10)

Yes, the temperature is within the confidence interval of (37.40, 37.60)

Yes, the temperature is within the confidence interval of (36.90, 38.10)

Answer 1

If the population standard deviation of a increases without other changes, the most likely event to happen to the confidence interval :

ans-> widens

a 90% confidence interval for the average temperature

Since 37.5 lies within the interval (37.4, 37.6), so we can say :

ans-> Yes, the temperature is within the confidence interval of (37.40, 37.60)