Nama Kelompok :8
Nama Ketua Kelompok : Nindya Prasanti
No Nama NPM Kontribusi Tingkat
Anggota kontribusi
Kelompok
1 Naila Atha 2306223982 Misal: terlibat aktif diskusi, menuliskan ringkasan 100%
Syahira hasil diskusi
2 Najwa 2306261532 Misal: terlibat aktif diskusi, menuliskan ringkasan 100%
Wirya hasil diskusi
Azzahra
3 Nindya 2306260920 Misal: terlibat aktif diskusi, menuliskan ringkasan 100%
Prasanti hasil diskusi
4 Rieckend 2306246090 Misal: terlibat aktif diskusi, menuliskan ringkasan 100%
Rahmadhani hasil diskusi
1. (5.56) On average, 3 traffice accidents per month occur at a certain intersection. What is the
probability that in any given month at this intersection
a) Exactly 5 accidents will occur?
b) Fewer than 3 accidents will occur?
c) At least 2 accidents will occur?
2. (5.62) The probability that a student at a local high school fails the screening test for scoliosis
(curvature of the spine) is known to be 0,004. Of the next 1875 students at the school who are
screened for scoliosis, find the probability that
a) Fewer than 5 fail the test
b) 8, 9, or 10 fail the test
3. (5.90) An oil drilling company ventures into various locations, and its success or failure is
independent from one location to another. Suppose the probability of a success at any specific
location is 0,25.
a) What is the probability that the driller drills at 10 locations and has 1 success?
b) The driller will go bankrupt if it drills 10 times before the first success occurs. What are the
driller’s prospects for bankruptcy?
4. (6.13) A research scientist reports that mice will live an average of 40 months when their diets
are sharply restricted and then enriched with vitamins and proteins. Assuming that the lifetime of
such mice are normally distributed with a standard deviation of 6.3 months, find the probability
that a given mouse will live
a) More than 32 months
b) Less than 28 months
c) Between 37 and 49 months
5. (6.23) The IQs of 600 applicants to a certain college are approximately normally distributed with
a mean of 115 and a standars deviation of 12. If the college requires an IQ of at least 95, how
many of these students will be rejected on this basis of IQ, regardless of their other
qualifications? Note that IQs are recorded to the nearest integers.
6. (6.25) A process for manufacturing an electronic component yields items of which 1% are
defective. A quality control plan is to select 100 items from the process, and if none are
defective, the process continues. Use the normal approximation to the binomial to find
a) The probability that the process continues given the sampling plan described
b) The probability that the process continues even if the process has gone bad (i.e., if the
frequency of defective components has shifted to 5.0% defective).
7. (8.23) The random variable X, representing the number of cherries in a cherry puff, has the
following probability distribution:
X 4 5 6 7
P(X = x) 0.2 0.4 0.3 0.1
a) Find the µ and the variance σ2 of X
b) Find the mean µx and the variance σ2x of the mean X for random samples of 36 cherry puffs
c) Find the probability that the average number of cherries in 36 cherry puffs will be less than
5.5
8. (8.26) The amount of time that a drive-through bank teller spends on a customer is a random
variable with mean µ = 3,2 minutes and a standard deviation 1,6 minutes. If a random sample of
64 customers is observed, find the probability that their mean time at the teller’s window is
a) At most 2,7 minutes
b) More than 3,5 minutes
c) Al least 3,2 minutes but less than 3,4 minutes
