seventy-five percent of the students graduating from high school in a small iowa farm town attend college…

seventy-five percent of the students graduating from high school in a small iowa farm town attend college. the towns chamber of commerce randomly selects 35 recent graduates and inquires whether or not they will attend college. find the probability that at least 85% of the surveyed students will be attending college. (round your answer to 4 decimal places)
Answer
Explanation:
Step1: Identify binomial parameters
$n = 35$, $p = 0.75$, $q = 1 - p = 0.25$
Step2: Determine the required number of successes
$k \geq 0.85 \times 35 = 29.75 \rightarrow k \geq 30$
Step3: State the binomial probability formula
$P(X = k) = \binom{n}{k} p^k q^{n-k}$
Step4: Calculate probability for $k=30$
$P(30) = \binom{35}{30} (0.75)^{30} (0.25)^5 \approx 0.05435$
Step5: Calculate probability for $k=31$
$P(31) = \binom{35}{31} (0.75)^{31} (0.25)^4 \approx 0.02630$
Step6: Calculate probability for $k=32$
$P(32) = \binom{35}{32} (0.75)^{32} (0.25)^3 \approx 0.00925$
Step7: Calculate probability for $k=33$
$P(33) = \binom{35}{33} (0.75)^{33} (0.25)^2 \approx 0.00231$
Step8: Calculate probability for $k=34$
$P(34) = \binom{35}{34} (0.75)^{34} (0.25)^1 \approx 0.00034$
Step9: Calculate probability for $k=35$
$P(35) = \binom{35}{35} (0.75)^{35} (0.25)^0 \approx 0.00003$
Step10: Sum the probabilities
$P(X \geq 30) = 0.05435 + 0.02630 + 0.00925 + 0.00231 + 0.00034 + 0.00003 = 0.09258$
Answer:
0.0926