The answer should be obtuse. I'm not sure why it is saying it's incorrect but none of the other answers make sense.
THIS IS THE COMPLETE QUESTION BELOW;
The weekly salaries of sociologists in the United States are normally distributed and have a known population standard deviation of 425 dollars and an unknown population mean. A random sample of 22 sociologists is taken and gives a sample mean of 1520 dollars.
Find the margin of error for the confidence interval for the population mean with a 98% confidence level.
z0.10 z0.05 z0.025 z0.01 z0.005
1.282 1.645 1.960 2.326 2.576
You may use a calculator or the common z values above. Round the final answer to two decimal places.
Answer
Margin error =210.8
Given:
standard deviation of 425
sample mean x=1520 dollars.
random sample n= 22
From the question We need to to calculate the margin of error for the confidence interval for the population mean .
CHECK THE ATTACHMENT FOR DETAILED EXPLANATION
Answer:
see explanation
Step-by-step explanation:
Using the trigonometric identity
sin²x + cos²x = 1
Consider the left side
2cos²A - 1 ← replace 1 by sin²A + cos²A
= 2cos²A - ( sin²A + cos²A)
= 2cos²A - sin²A - cos²A
= cos²A - sin²A = right side ⇒ verified
Answer:
Step-by-step explanation:
Divide so you get a decimal. 1/2 = 0.5. 2/3 = 0.666
0.666 > 0.5
So 1/2 is less than 2/3
Let, the speed of boat = x
Speed of current = y
So, x + y = 280/7
x + y = 40 ---- first equation
x - y = 280/14
x - y = 20
x = 20 + y
Substitute this value of x in first equation,
20 + y + y = 40
2y = 40 - 20
y = 20/2
y = 10
Substitute this in first equation,
x + 10 = 40
x = 30
In short, Speed of Boat = 30 mph, & speed of current = 10 mph
Hope this helps!