Confidence interval

Posted: August 27th, 2021

Module 5

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Module 5

Question 1- Confidence interval

Therefore, in form of

Question 2- 95% Confidence interval

Let X be the number of presidents who are taller than their opponents

Normal approximation is used to find confidence interval for true proportion

=

Question 3- 99% Confidence interval

1. Preliminary Estimate Unknown Proportion

Thus, the sample size (n) is approximately 553

• Preliminary Estimate of Known Proportion

Thus, the sample size (n) is approximately 489

Question 4- Airport speeds in MPBS

• A. Because the sample size of 50 is greater than 30, the distribution of sample means can be treated as a normal distribution.

Question 5- Lowering cholesterol levels

, , , ,

From the table t value is 1.6787

Upper limit =

Lower limit =

Therefore,

C. The confidence interval limits do not contain 0, suggesting the garlic treatment did affect the LDL cholesterol levels.

Question 6- Adults Male and Female

Adult female;

, , , ,

From the table t value is 1.2413

Upper limit =

Lower limit =

Therefore,

Adult female;

, , , ,

From the table t value is 1.2413

Upper limit =

Lower limit =

Therefore,

A. The confidence intervals do not overlap, so it appears that adult females have a significantly higher mean pulse rate than adult males.

Question 7- Adults Pulse Rate

From the tables, = 2.05

1. Sample Size

The Standard deviation is calculated as follows;

= 19

Therefore, the required sample size (n) is given by;

Sample size is approximately 380

• Sample Size (N) Of

Sample size is approximately 118

• Part A Results Are Likely to be Better.