Answer:
In directing any measurable investigation (right now for mean, for example channeling t-test for mean) the most significant suspicions are as per the following:
The typicality of populace about which ends are being drawn. This implies the populace from which the example has been drawn ought to be at any rate roughly ordinarily circulated. This is a significant supposition and whenever damaged , the test can't be directed by any stretch of the imagination. This supposition may or may not be valid right now. In this way any further test or calculation of certainty interim for mean, would have neither rhyme nor reason.
Furthermore, the conduction of this t test for development of certainty interim additionally doesn't work if there is any exceptions present in the example. There can be an extremely youthful President or an old as well, yet his age will be an anomaly.
In this way, the end dependent on Joe's examination may be deceiving.