PLEASE HELP 100 POINTS AND BRAINLY
2 answers:
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Answer:
a) 61.2, b) 38.4 and c) 4.98
Step-by-step explanation:
Given:
The mean width of 12 I-Pads is 5.1 inches.
The mean width of 8 Kindles is 4.8 inches.
Question asked:
a. What is the total width of the I-Pads?
b. What is the total width of the Kindles?
c. What is the mean width of the 12 I-Pads and 8 Kindles?
Solution:
<u>As we know:</u>
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a) Thus, the total width of the I-Pads are 61.2 inches.
b) Thus, total width of the Kindles are 38.4 inches.
Combined width of both I-pad and Kindles = 61.2 + 38.4 = 99.6 inches
Combined number of observations = 12 + 8 =20
Combined mean of width of the 12 I-Pads and 8 Kindles = Combined width of both I-pad and Kindles Combined number of observations
Combined mean of width of the 12 I-Pads and 8 Kindles =
c) Thus, the mean width of the 12 I-Pads and 8 Kindles is 4.98 inches.
<h2><u>Answer with explanation:</u></h2>
The confidence interval for population mean (when population standard deviation is unknown) is given by :-
, where n= sample size
= Sample mean
s= sample size
t* = Critical value.
Given : n= 25
Degree of freedom :
Significance level for 98% confidence interval :
Using t-distribution table ,
Two-tailed critical value for 98% confidence interval :
⇒ The critical value that should be used in constructing the confidence interval = 2.4922
Then, the 95% confidence interval would be :-
Hence, the 98% confidence interval for the mean repair cost for the dryers. =