Math 2311 EMCF Popper 5-Consider a uniform distribution that is defined for

Subject: Mathematics / Statistics
Math 2311EMCF Popper 5 (Sections 4.1 – 4.4)
Instructions• Popper will NOT be accepted through email or in person.
Popper must be submitted through CourseWare BEFORE the deadline. • Submit this assignment at under "EMCF"
Popper 5
1. Consider a uniform distribution that is defined for
. What is
the probability that X lies between 1 and 2? (Hint: draw a picture)
a. 2.5
b. 0.625
c. 0.25
d. 0.75
e. none of these
2. The distribution of raw scores on a chemistry final is approximately
normal with mean of about 50 and standard deviation of about 10. What
is the probability that a student will have a raw score that is more than
a. 0.7238
b. 0.3085
c. 0.4500
d. 0.6915
e. none of these
3. Consider problem 2 above. Give the interval for the middle 95% of
a. [45, 55] b. [30, 70]
c. [20, 80]
d. [40, 60]
e. none of these
4. True or False: The standard normal distribution has a mean of 1.
a. True
b. False 5. True or False: The 70th percentile means 70% of the values in the
distribution are above it.
a. True b. False 6. True or False: On a statistics exam, Joe’s score was at the 20th percentile
and John’s score was at the 40th percentile; thus, we can say that John’s
score was twice Joe’s. a. True b. False 7. True or False: On the standard normal curve, the 50th percentile
corresponds to the mean value of the data set. a. True b. False 8. True or False: If a student’s exam score corresponds to a negative zscore, then the student has a score that is less than the mean of the set of
exam scores. a. True b. False 9. If a sample has a mean of 48 and a standard deviation of 3.2, what is the
value in the set that corresponds to a z-score of -1.6?
a. 38.22 b. 42.88c. 53.12d. 46.40e. none of these 10. Find P(-1.2<Z<1.9)
a. 0.9713b. 0.8562c. 0.8020d. 0.7659e. none of these
11. Find c such that P(Z>c)=0.3859
a. -0.29b. 0.35c. -0.35d. 0.29e. none of these
12. If a population has a standard deviation , then the standard
deviation of the mean of 100 randomly selected items from this
population is
a. /100 b.
c. /10 d. 100
e. 1
f. none of these
13. The sampling distribution of a statistic isa. The probability that we
obtain the statistic in repeated random samplesb. The mechanism that
determines whether randomization was effectivec. The distribution of
values taken by a statistic in all possible samples of the same sample size
from the same population d. The extent to which the sample results
differ systematically from the truthe. None of these
14. The expected value of the sampling distribution of the sample mean
is equal to a. the standard deviation of the sampling populationb. the
mean of the sampling populationc. the median of the sampling
d. the population size e. none of these

15. Power companies kill trees growing near their lines
to avoid power failures due to falling limbs in storms. Applying a
chemical to slow the
growth of the trees is cheaper than trimming, but the chemical kills some
of the trees. Suppose that one such chemical would kill 15% of
sycamore trees. The power company tests the chemical on 200
sycamores. Consider these a SRS from the population of all sycamore
trees. What is the probability that no more than 32 trees are killed?
a. 0.0571b. 0.6540c. 0.3460d. 0.1598e. none of these