You have taken a random sample of size n = 19 from a normal population that has a population mean of μ=50 and a population standard deviation of a = 15. Your sample, which is Sample 1 in the table below, has a mean of x=45.3. (In the table, Sample 1 is written "S1", Sample 2 is written "S2", etc.) (a) Based on Sample 1, graph the 75% and 90% confidence intervals for the population mean. Use 1.150 for the critical value for the 75% confidence interval, and use 1.645 for the critical value for the 90% confidence interval. (If necessary, consult a list of formulas.) • Enter the lower and upper limits on the graphs to show each confidence interval. Write your answers with one decimal place. • For the points (and ◆), enter the population mean, μ = 50.

Glencoe Algebra 1, Student Edition, 9780079039897, 0079039898, 2018
18th Edition
ISBN:9780079039897
Author:Carter
Publisher:Carter
Chapter10: Statistics
Section10.1: Measures Of Center
Problem 9PPS
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You have taken a random sample of size n = 19 from a normal population that has a population mean of μ = 50 and a population standard deviation of o=15.
Your sample, which is Sample 1 in the table below, has a mean of x =45.3. (In the table, Sample 1 is written "S1", Sample 2 is written "S2", etc.)
(a) Based on Sample 1, graph the 75% and 90% confidence intervals for the population mean. Use 1.150 for the critical value for the 75% confidence
interval, and use 1.645 for the critical value for the 90% confidence interval. (If necessary, consult a list of formulas.)
• Enter the lower and upper limits on the graphs to show each confidence interval. Write your answers with one decimal place.
• For the points (and ◆), enter the population mean, μ = 50.
37.0
75% confidence interval
|||||||
37.0
51.5
|||||||||||
66.0
75% 75% 90% 90%
lower upper lower upper
limit limit limit limit
?
?
?
S1
45.3
?
S2 48.2 44.2
S3 52.4 48.4
S4 47.7 43.7
S5 52.3 48.3
S6 43.3 39.3
S7 43.4 39.4
52.2 42.5 53.9
56.4 46.7 58.1
51.7 42.0 53.4
56.3 46.6 58.0
47.3 37.6 49.0
47.4 37.7 49.1
S8 56.5 52.5 60.5 50.8
62.2
S9 47.2 43.2
51.2 41.5
52.9
51.7
53.4
42.0
53.2 43.5 54.9
47.5 37.8 49.2
S10 47.7 43.7
S11 49.2 45.2
S12 43.5 39.5
S13 45.2 41.2
S14 51.3 47.3
S15 48.4 44.4
49.2 39.5 50.9
55.3 45.6 57.0
52.4 42.7 54.1
S16 51.7 47.7
S17 51.6 47.6
55.7 46.0 57.4
55.6 45.9 57.3
58.7
S18 54.7 50.7
49.0 60.4
S19 48.8 44.8
52.8 43.1 54.5
S20 47.2 43.2 51.2 41.5 52.9
37.0
66.0
37.0
|++++++
37.0
75% confidence intervals
90% confidence interval
(b) Press the "Generate Samples" button below to simulate taking 19 more samples of size n = 19 from the population. Notice that the confidence
intervals for these samples are drawn automatically. Then complete parts (c) and (d) below the table.
+|||||||||
51.5
66.0 37.0
66.0
90% confidence intervals
66.0
||||||
66,0
Transcribed Image Text:You have taken a random sample of size n = 19 from a normal population that has a population mean of μ = 50 and a population standard deviation of o=15. Your sample, which is Sample 1 in the table below, has a mean of x =45.3. (In the table, Sample 1 is written "S1", Sample 2 is written "S2", etc.) (a) Based on Sample 1, graph the 75% and 90% confidence intervals for the population mean. Use 1.150 for the critical value for the 75% confidence interval, and use 1.645 for the critical value for the 90% confidence interval. (If necessary, consult a list of formulas.) • Enter the lower and upper limits on the graphs to show each confidence interval. Write your answers with one decimal place. • For the points (and ◆), enter the population mean, μ = 50. 37.0 75% confidence interval ||||||| 37.0 51.5 ||||||||||| 66.0 75% 75% 90% 90% lower upper lower upper limit limit limit limit ? ? ? S1 45.3 ? S2 48.2 44.2 S3 52.4 48.4 S4 47.7 43.7 S5 52.3 48.3 S6 43.3 39.3 S7 43.4 39.4 52.2 42.5 53.9 56.4 46.7 58.1 51.7 42.0 53.4 56.3 46.6 58.0 47.3 37.6 49.0 47.4 37.7 49.1 S8 56.5 52.5 60.5 50.8 62.2 S9 47.2 43.2 51.2 41.5 52.9 51.7 53.4 42.0 53.2 43.5 54.9 47.5 37.8 49.2 S10 47.7 43.7 S11 49.2 45.2 S12 43.5 39.5 S13 45.2 41.2 S14 51.3 47.3 S15 48.4 44.4 49.2 39.5 50.9 55.3 45.6 57.0 52.4 42.7 54.1 S16 51.7 47.7 S17 51.6 47.6 55.7 46.0 57.4 55.6 45.9 57.3 58.7 S18 54.7 50.7 49.0 60.4 S19 48.8 44.8 52.8 43.1 54.5 S20 47.2 43.2 51.2 41.5 52.9 37.0 66.0 37.0 |++++++ 37.0 75% confidence intervals 90% confidence interval (b) Press the "Generate Samples" button below to simulate taking 19 more samples of size n = 19 from the population. Notice that the confidence intervals for these samples are drawn automatically. Then complete parts (c) and (d) below the table. +||||||||| 51.5 66.0 37.0 66.0 90% confidence intervals 66.0 |||||| 66,0
16
(c) Notice that for
20
correct statement.
= 80% of the samples, the 90% confidence interval contains the population mean. Choose the
When constructing 90% confidence intervals for 20 samples of the same size from the population, at most 90% of
the samples will contain the population mean.
When constructing 90% confidence intervals for 20 samples of the same size from the population, exactly 90% of
the samples must contain the population mean. There must have been an error with the way our samples were
chosen.
When constructing 90% confidence intervals for 20 samples of the same size from the population, the percentage of
the samples that contain the population mean should be close to 90%, but it may not be exactly 90%.
(d) Choose ALL that are true.
The 75% confidence interval for Sample 15 indicates that 75% of the Sample 15 data values are between 44.4
and 52.4.
From the 90% confidence interval for Sample 15, we cannot say that there is a 90% probability that the
population mean is between 42.7 and 54.1.
If there were a Sample 21 of size n=38 taken from the same population as Sample 15, then the 90% confidence
interval for Sample 21 would be narrower than the 90% confidence interval for Sample 15.
The 75% confidence interval for Sample 15 is narrower than the 90% confidence interval for Sample 15. This is
coincidence; when constructing a confidence interval for a sample, there is no relationship between the level of
confidence and the width of the interval.
None of the choices above are true.
Transcribed Image Text:16 (c) Notice that for 20 correct statement. = 80% of the samples, the 90% confidence interval contains the population mean. Choose the When constructing 90% confidence intervals for 20 samples of the same size from the population, at most 90% of the samples will contain the population mean. When constructing 90% confidence intervals for 20 samples of the same size from the population, exactly 90% of the samples must contain the population mean. There must have been an error with the way our samples were chosen. When constructing 90% confidence intervals for 20 samples of the same size from the population, the percentage of the samples that contain the population mean should be close to 90%, but it may not be exactly 90%. (d) Choose ALL that are true. The 75% confidence interval for Sample 15 indicates that 75% of the Sample 15 data values are between 44.4 and 52.4. From the 90% confidence interval for Sample 15, we cannot say that there is a 90% probability that the population mean is between 42.7 and 54.1. If there were a Sample 21 of size n=38 taken from the same population as Sample 15, then the 90% confidence interval for Sample 21 would be narrower than the 90% confidence interval for Sample 15. The 75% confidence interval for Sample 15 is narrower than the 90% confidence interval for Sample 15. This is coincidence; when constructing a confidence interval for a sample, there is no relationship between the level of confidence and the width of the interval. None of the choices above are true.
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