Discover the answers to your questions at Westonci.ca, where experts share their knowledge and insights with you. Explore thousands of questions and answers from knowledgeable experts in various fields on our Q&A platform. Experience the ease of finding precise answers to your questions from a knowledgeable community of experts.

The following hypothetical data represent a sample of the annual numbers of home fires started by candles for the past several years.
5640, 5090, 6590, 6380, 7165, 8440, 9980
The population has a standard deviation equal to 1210. Assuming that the data is from a distribution that is approximately normal, construct a 90 % confidence interval for the mean number of home fires started by candles each year


Sagot :

fichoh

Answer:

(6290.678 ; 7790.742)

Step-by-step explanation:

Given the data :

5640, 5090, 6590, 6380, 7165, 8440, 9980

The sample mean, xbar = Σx / n = 49285 / 7 = 7040.71

The 90% confidence interval :

Xbar ± Margin of error

Margin of Error = Zcritical * σ/√n

Since the σ is known, we use the z- distribution

Zcritical at 90% confidence = 1.64

Hence,

Margin of Error = 1.64 * 1210/√7

Margin of Error = 750.032

90% confidence interval is :

7040.71 ± 750.032

Lower boundary = 7040.71 - 750.032 = 6290.678

Upper boundary = 7040.71 + 750.032 = 7790.742

(6290.678 ; 7790.742)