 |
|
|
|
|
Solutions for Session 3, Part C
See solutions for Problems: C1 | C2 | C3 | C4 | C5
 |
Problem C1 | |
a. | Adding the percentages shows us that 90.4% of the responses are in the 70s and below. |
b. | Adding the percentages shows us that 9.6% are 80 or higher. |
c. | Adding the percentages shows us that 42.3% are in the 50s and below. |
d. | Adding the percentages shows us that 57.7% are 60 or higher. |
e. | All of them (100%) are less than 100. |
f. | Adding the percentages shows us that 69.2% are at least 40 but below 70. |
g. | This question cannot be answered using only this relative frequency table, since we are not told how many responses are in the interval 65 to < 70; we only know how many are in the interval 60 to <70. |
h. | This question cannot be answered using only this relative frequency table, since we do not know how many responses are in the interval 30 to < 35. |
i. | This question cannot be answered using only this relative frequency table, since we do not know how many responses are exactly 60 -- only that 34.6% are in the interval 60 to < 70. |
<< back to Problem C1
|
|
| |
|
Problem C2 | |
|
For questions (g) and (h), we might guess that half the responses will be in the lower range (60-64 and 30-34) and the other half will be in the upper range (65-69 and 35-39).
For question (g), we know that 23.1% of the responses are 70 or above and 34.6% are in the interval 60 to < 70. Half of 34.6% is 17.3%, which gives us an estimate of 23.1% + 17.3% = 40.4% for the percentage of responses that are 65 or greater.
For question (h), we know that 7.7% of the responses are in the interval 30 to < 40. Half of this is 3.85% (or 3.9%), which is our estimate for the percentage of responses less than 35.
<< back to Problem C2
|
|
|
|
| |
|
Problem C4 | |
a. | Forty-seven responses are in the 70s and below. |
b. | Five responses are 80 or higher (52 - 47). |
c. | Twenty-two responses are in the 50s and below. |
d. | Thirty responses are 60 or higher (52 - 22). |
e. | All 52 responses are less than 100. |
f. | Thirty-six responses are at least 40 but less than 70 (40 - 4). |
Questions (g), (h), and (i) cannot be answered because the table only gives answers in intervals of 10, and these questions ask about smaller intervals.
<< back to Problem C4
|
|
|
| |
|
Problem C5 | |
a. | Using only the relative cumulative frequencies, 90.4% of the responses are in the 70s and below. |
b. | Using only the relative cumulative frequencies, 9.6% of the responses are 80 or higher (100 - 90.4). |
c. | Using only the relative cumulative frequencies, 42.3% of the responses are in the 50s and below. |
d. | Using only the relative cumulative frequencies, 57.7% of the responses are 60 or higher (100 - 42.3). |
e. | All of the responses (100%) are less than 100. |
f. | Using only the relative cumulative frequencies, 69.2% of the responses are at least 40 but less than 70 (76.9 - 7.7). |
<< back to Problem C5
|
|
|
