Does the frequency distribution given appear to be normal?
Score Frequency
65-69 4
70-74 5
75-79 6
80-84 4
85-89 6
90-94 4
95-99 5
Yes, the frequencies preceding the maximum are roughly a mirror image of those that follow the maximum
No, there is not a concentration of frequencies in the middle
Yes, there is symmetry in the distribution THIS ONE
No, the frequencies increase, reach a maximum, then decrease
Does the frequency distribution appear to have a normal distribution using a strict interpretation of the relevant criteria?
Speed Number of cars
0-29 4
30-59 16
60-89 60
90-119 20
No, the distribution is not symmetric THIS ONE
No, the frequency do not increase from the low frequency to a maximum frequency
Yes, all the requirements are met
To determine whether a frequency distribution appears to be normal, you can consider the symmetry of the distribution. In the first example, the frequencies preceding the maximum are roughly a mirror image of those that follow the maximum. This indicates that there is symmetry in the distribution, which is a characteristic of a normal distribution. Therefore, the answer to the first question is "Yes, there is symmetry in the distribution."
In the second example, the distribution is not symmetric. The frequency of cars increases from the low frequency category to the middle category (60-89), but then decreases in the next category (90-119). This violates the requirement of a normal distribution where frequencies should increase from the low frequency to a maximum frequency and then decrease. Therefore, the answer to the second question is "No, the distribution is not symmetric."