Assume that when adults with smartphones are randomly selected, 5252% use them in meetings or classes. If 1010 adult smartphone users are randomly selected, find the probability that fewer than 55 of them use their smartphones in meetings or classes.
The probability is
(Type an integer or decimal rounded to four decimal places as needed.)
Probability that adults with smartphones use them in meetings or classes = 0.52
Let X be the number of adults with smartphones use them in meetings or classes out of randomly selected 10 users.
Then X ~Binomial(n = 10, p = 0.52)
Probability that fewer than 5 of them use their smartphones in meetings or classes = P(X < 5)
= P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4)
= 10C0 * 0.520 * (1 - 0.52)10 + 10C1 * 0.521 * (1 - 0.52)9 + 10C2 * 0.522 * (1 - 0.52)8 + 10C3 * 0.523 * (1 - 0.52)7 + 10C4 * 0.524 * (1 - 0.52)6
= 0.0006 + 0.0070 + 0.0343 + 0.0991 + 0.1878
= 0.3288
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