Answer:
A) 
B) T = -5 °C
Step-by-step explanation:
A) Let T be the change in temperature of the week. T is determined as the total temperature change (-20°C) divided by the number of weeks that have passed (4 weeks). The expression is:

B) In order to simplify the expression, simply perform the division.

This means that the temperature has dropped by 5 degrees each week.
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.
<h3>
<u>QU</u><u>ESTION</u><u>:</u></h3>
WHAT IS THE PRODUCT OF: 7.21 x 4.2
PLEASE--
<h3>SOLUTION AND ANSWER:</h3>

THEREFORE, <em><u>30.282</u></em> IS THE PRODUCT
HOPE THIS HELP YOU! HAVE A NICE DAY!
~kimtaetae92~
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