Stats I need help with these two stats questions I do not kn

?Stats! I need help with these two stats questions. I do not know how to construct confidence intervals on #3 nor what test stat to use on question #4. Please show steps.

3. Upon leaving college, you decide to do some volunteer medical service in a poor rural community. Many of the children seem to be undernourished and appear to be anemic. People with less than 12 grams of hemoglobin per deciliter of blood are considered anemic. You saw 36 children and found that the mean amount of hemoglobin was 11.3 g/dl and the standard deviation was 1.5 g/dl. Construct two 95% confidence intervals, one for the mean and one for the standard deviation, for the hemoglobin level for the children in this community. Comment on your findings relative to the standard definition of anemic given above. 4. A manufacturer makes ball bearings for a very precise mechanical application. The bearings are supposed to have a mean diameter of 1.150 cm. The customer\'s machines have been breaking down frequently, so it is suspected that the mean diameter is not equal to 1.150 cm. To test this, the customer takes a random sample of 28 bearings from a recent shipment of replacement bearings and finds that they have a mean diameter of 1.151 cm with a standard deviation of 0.0018 cm. Use a 0.01 significance level to test whether the bearings meet the stringent specifications. Based on your results, make a recommendation on whether the customer should continue to use this particular manufacturer, or find a new one.

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