After constructing a relative frequency distribution summarizing iq scores of college students, what should be the sum of the relative frequencies?

a. if percentages are used, the sum should be a 100%. if proportions are used, the sum should be 1.
b. if percentages are used, the sum should be 1%. if proportions are used, the sum should be 100.
c. if percentages are used, the sum should be 0. if proportions are used, the sum should be 0.
d. if percentages are used, the sum should be 100%. if proportions are used, the sum should be 100.

Explanation:

The relative frequency can be measured as a ratio (proportion) or as a percentage.

As a ratio, the relative frequency is the number of times that the desired outcome is observed (either theoretically or experimentally) divided by the total number of  possible outcomes (theoretically) or  observed (experimentally).

As a percentage, the relative frequency is the ratio multiplied by 100.

This shows it mathematically:

                                       = sum of all (n) frequencies / number of events =

                                       = number of events / number of events = 1

As a percentage, total relative frequency = 1 × 100 = 100

she will sew have sewn five dresses   and be 1/3 done with the sixth one in an hour.

step-by-step explanation:

3/4 of an hour=45 mins

lucy makes 1 dress per 11.25 minutes

45 mins+11.25 mins=56.25 mins

60 mins- 56.25 mins=3.75 mins

3.75 mins is 1/3 of of 11.25 mins

therefore she the other 1/3 would be part of the hour and she will have sewn 5 dresses and begun the sixth.

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