Answer:
b) The width of the confidence interval becomes narrower when the sample mean increases.
Step-by-step explanation:
The confidence interval can be calculated as:

a) The width of the confidence interval becomes wider as the confidence level increases.
The above statement is true as the confidence level increases the width increases as the absolute value of test statistic increases.
b) The width of the confidence interval becomes narrower when the sample mean increases.
The above statement is false. As the sample mean increases the width of the confidence interval increases.
c) The width of the confidence interval becomes narrower when the sample size n increases.
The above statement is true as the sample size increases the standard error decreases and the confidence interval become narrower.
1. not equal to
2. equal to
6% or 0.06 is the simple interest rate the bank pays him.
<u>Step-by-step explanation:</u>
Sir Ving Spoon earned $5,436 on his $7,550 certificate of deposit.
From this given information,
It can be determined that the Principal amount is $7550 and the interest amount is $5436.
The CD is for 12 years. Therefore, the number of years is 12.
<u>To find the interest rate (r) :</u>
Using the simple interest formula,
Interest = P×r×t
where,
- P is the principal amount = $7550
- r is the rate of interest.
- t is the number of years = 12
⇒ 5436 = 7550 × r × 12
⇒ 5436 = 90600 × r
⇒ r = 5436 / 90600
⇒ r = 0.06
Multiply by 100 to represent in rate %
⇒ r = 0.06 × 100
⇒ r = 6%
∴ 6% or 0.06 is the simple interest rate the bank pays him.
After a series of calculations using the interest formula:
The best and most correct answer among the choices provided by your question is the second choice or letter B "$0.18."
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