Question

1.)

A distribution of values is normal with a mean of 240 and a standard deviation of 8.

Find the interval containing the middle-most 84% of scores:

Enter your answer accurate to 1 decimal place using interval notation. Example: (2.1,5.6)


Hint: To work this out, 1) sketch the distribution, 2) shade the middle 84% of the data, 3) label unkown data values on the horizontal axis just below the upper and lower ends of the shaded region, 4) calculate the percentage (area) to the left of the lowermost unknown data value, 5) calculate the TOTAL percentage (area) to the LEFT of the uppermost unknown data value, 6) use invnorm to calculate the lowermost data value, 7) use invnorm to calculate the uppermost data value. The data values you get from steps 6 and 7 are used to answer the question.

2.)

A particular fruit's weights are normally distributed, with a mean of 335 grams and a standard deviation of 34 grams.

The heaviest 6% of fruits weigh more than how many grams?

Give your answer to the nearest gram.

Answer 1