Answer:
The interval from the sample of size 400 will be approximately <u>One -half as wide</u> as the interval from the sample of size 100
Step-by-step explanation:
From the question we are told the confidence level is 95% , hence the level of significance is
=>
Generally from the normal distribution table the critical value of is
Generally the 95% confidence interval is dependent on the value of the margin of error at a constant sample mean or sample proportion
Generally the margin of error is mathematically represented as
Here assume that is constant so
=>
=>
So let and
=>
=>
=>
So From this we see that the confidence interval for a sample size of 400 will be half that with a sample size of 100
Answer:
87.9
Step-by-step explanation:
Use a calculator or table to find the z-score that corresponds to 25%.
P(Z < z) = 0.25
z = -0.675
Now find the value that corresponds to that z score.
z = (x − μ) / σ
-0.675 = (x − 101.3) / 19.9
x = 87.9
Answer:
1, 2.2, 5.5, 10.2.
Step-by-step explanation: these are simplified to the nearest tenth
Answer:
170
Step-by-step explanation:
Ann, Ben, and Cindy were eating strawberries.
The ratio of the numbers of berries they ate is 5:5:7.
If Cindy ate 30 strawberries less than Ann and Ben together,
find:
what is the total number of strawberries the three of them ate?
solution:
add the ratios 5 + 5 + 7 = 17
since Cindy ate 30, less than Ann and Ben together so, the equation is
7x = 5x + 5x - 30
7x - 10x = -30
x = 30/3
x = 10
ann 5 x 10 = 50
ben 5 x 10 = 50
cindy 7 x 10 = 70
total = 170