Answer: a) (1008.34,1019.658) b) (1009.24,1018.76)
Step-by-step explanation:
Since we have given that
n = 75
mean = 1014 hours
Standard deviation = 25 hours
At 95% two sided , z = 1.96
So, confidence interval would be

(b) Construct a 95% lower confidence bound on the mean life.
z = 1.65
So, confidence interval would be

Hence, a) (1008.34,1019.658) b) (1009.24,1018.76)
Hello! For this you are just going to do this step by step, and remember to use PEMDAS. That is the order in which you should do the math. The abbreviation stands for Parenthesis, exponents, multiplication, division, addition and subtraction. So lets get started!
<span><span>(<span><span><span><span>(<span><span><span><span><span>15<span>y0</span></span><span>x<span>−3</span></span></span><span>z2</span></span>3</span><span>x3</span></span>)</span><span>(<span>y7</span>)</span></span><span>z1</span></span>2</span>)</span>2</span><span>=<span><span><span>254</span><span><span><span>x6</span><span>y14</span></span><span>z6</span></span></span><span>x6</span></span></span><span>=<span><span>254</span><span><span>y14</span><span>z6</span></span></span></span>
Hope this helps!! If you need any more help or further explanation just let me know!! :)
20,146,974. 78,901,234. 46,123,086.
76,543,218. 54,876,547
OK im answering ............................................................................................................