Download Sample multiple choice problems(2).

ELEMENTARY STATISTICS
MULTIPLE CHOICE SAMPLE TWO.
Page 1 of 2.
Assume
answers with decimals are rounded. ANSWER (e) IS ALWAYS "None of (a), (b), (c) , (d) is correct." Answer all
questions. Use 882E Scantron. Do not write on this sheet - return it with your scratch paper & your Scantron.
1.)
For the binomial distribution with n = 46 and p = 1/4, find the probability of 10 to 20
successes, inclusive. (a) 0.62146
(b) 0.74502
(c) 0.89429
(d) 0.913996
2.)
A machine produces gaskets whose thickness is normally distributed with mean 2.50 mm,
and standard deviation 0.04 mm. Find the probability that the thickness of a randomly
chosen gasket exceeds 2.515 mm.
(a) 0.70766
(b) 0.35383
(c) 0.11784
(d) 0.23568
3.)
A machine produces gaskets whose thickness is normally distributed with mean 2.50 mm,
and standard deviation 0.04 mm. Find the probability that the mean thickness of a sample
of size 10 exceeds 2.515 mm.
(a) 0.70766
(b) 0.35383
(c) 0.11784
(d) 0.23568
4.)
A machine bakes loaves whose size is normally distributed. A sample of size 25 has a mean
size of 16.2 oz with sample standard deviation 0.15 oz.. Find the 90% confidence interval for
the mean size of all loaves.
(a) 16.151 oz to 16.249 oz
(c) 16.149 oz to 16.251 oz
(b) 15.870 oz to 16.530 oz
(d) 15.975 oz to 16.425 oz
5.)
A machine produces gaskets which are to be between 2.46 mm and 2.54 mm in thickness.
Assume the thickness of the gaskets is normally distributed with mean 2.50 mm.
What should the standard deviation be so that only 1% of the gaskets fail be the specified
thickness?
(a) 0.01553 mm
(b) 0.01719 mm
(c) 0.02326 mm (d) 0.02576 mm
6.)
A machine produces bolts whose length is normally distributed. A sample of size 10 has a
mean length of 9.00 cm, and sample standard deviation of 0.05 cm. Find the 90% confidence
interval for the mean length of all bolts.
(a) 8.971 cm to 9.029 cm
(c) 8.733 cm to 9.267 cm
(b) 8.918 cm to 8.082 cm
(d) 8.974 cm to 9.026 cm
7.)
For a sample of size 40, find the right-hand chi-square critical value for a 94% confidence
interval.
(a) 54.761
(b) 53.584
(c) 57.215
(d) 58.428
8.)
In sampling for a 96% confidence interval for the population proportion, we want the margin
of error to be under 0.035. What should the minimum sample size be if no estimate is
available for the population propportion?
(a) 3444
(b) 861
(c) 860
(d) 3443
9.)
In a random sample of 220 cars, 22 need an oil change. Find the margin of error for a
95% confidence interval for the percentage of cars needing an oil change.
(a) 0.039642
(b) 0.0332688
(c) 0.02417
(d) 0.02808
GO TO PAGE 2
ELEMENTARY STATISTICS
MULTIPLE CHOICE SAMPLE TWO.
Page 2 of 2.
Assume
answers with decimals are rounded. ANSWER (e) IS ALWAYS "None of (a), (b), (c) , (d) is correct." Answer all
questions. Use 882E Scantron. Do not write on this sheet - return it with your scratch paper & your Scantron.
10.) In a random sample of 220 cars, 22 need an oil change. Find the 95% confidence interval
for the percentage of cars needing an oil change.
(a) (0.0547, 0.1453) (b) (0.0667, 0.1333) (c) (0.0496, 0.0504) (d) (0.0604, 0.1396)
11.) For the binomial distribution with n = 42 and p = 0.3, estimate the probability of 10 to 16
successes, inclusive, by using normal approximation.
(a) 0.75716 (b) 0.68320
(c) 0.92215 (d) 0.75568
12.) Find the critical value of t, t(0.045, 12).
(a) 1.844
(b) 1.844 (c) 1.695 (d) 1.695
13.) The margin of error is to be 0.15 in a 98% confidence interval for the proportion. What
should the minimum sample size be? Assume we cannot estimate p.
(a) 16
(b) 241
(c) 60
(d) 61
14.) The critical value of  2 ,  2 (0.045, 9), is approximately
(a) 3.218
(b) 17.246
(c) 8.863
ANSWERS: 1) b 2) b 3) c
13) d 14) b
GO TO PAGE 3
4) c
5) a
6) a
7) c
8) b
(d) 20.483
9) a
10) d 11) a 12) b