Answer: 
Step-by-step explanation:
The confidence interval for population mean is given by :-

Given : Sample mean :
hours
Standard deviation
hours
Sample size : n=90, which is a large sample(n<30), so we use z-test.
Significance level: 
Critical value : 
Then , the confidence interval for population mean will be :-

Hence, the 90% confidence interval for the mean life
of all light bulbs of this type. is 
Hello there!
Monday: 9.75 x 4 = 39
Tuesday: 9.75 x 6 = 58.5
Wednesday: 9.75 x 5 = 48.75
Thursday: 9.75 x 5 = 48.75
Friday: 9.75 x 7 = 68.25
Now, add all these together to get the gross pay: 39 + 58.5 + 48.75 + 48.75 + 68.25 = 263.25
Hope I helped!
I am not sure what the question is here. I can tell you how to find the percent of kids that developed influenza in that class. We can compare it to the 20% of students nationwide. There could many different questions that stem from the piece of information you gave.
To find the percent of kids that developed influenza in that class do 6÷15 which gives you
.4 and written as a percent would be 40%.
Please message me if you have any questions! Hope this helps!
Answer: ×/2 + 9 =
Step-by-step explanation: when a sentence needs to be visualized it is best to strat from the outside.
So if nine more than blah blah equals 21,
... +9 = 21
it's 18 with a remainder of 13. I attached a photo that shows the work of it