If a numerical property, and any sample of data from it, can take on any value from a continuous range instead of, for example, just integers, then the probability of a number falling into some range of possible values can be described by integrating a continuous probability distribution across this range, even when the naive probability for a sample number taking one certain value from infinitely many is zero.
ɪf ɐ nuːmˈɛɹɪkəl pɹˈɑːpɚɾi, ænd ˌɛni sˈæmpəl ʌv dˈeɪɾə fɹʌm ɪt, kæn tˈeɪk ˌɔn ˌɛni vˈæljuː fɹʌm ɐ kəntˈɪnjuːəs ɹˈeɪndʒ ɪnstˈɛd ʌv, fɔːɹ ɛɡzˈæmpəl, dʒˈʌst ˈɪntɪdʒɚz, ðˈɛn ðə pɹˌɑːbəbˈɪlᵻɾi əvə nˈʌmbɚ fˈɔːlɪŋ ˌɪntʊ sˌʌm ɹˈeɪndʒ ʌv pˈɑːsᵻbəl vˈæljuːz kæn biː dᵻskɹˈaɪbd baɪ ˈɪntᵻɡɹˌeɪɾɪŋ ɐ kəntˈɪnjuːəs pɹˌɑːbəbˈɪlᵻɾi dˌɪstɹɪbjˈuːʃən əkɹˌɑːs ðɪs ɹˈeɪndʒ, ˈiːvən wɛn ðə naɪˈiːv pɹˌɑːbəbˈɪlᵻɾi fɚɹə sˈæmpəl nˈʌmbɚ tˈeɪkɪŋ wˈʌn sˈɜːʔn̩ vˈæljuː fɹʌm ˈɪnfɪnətli mˈɛni ɪz zˈiəɹoʊ.