Answer:
D. We can be 95% confident that the proportion of all cell phone users who use text messaging is between 73.1% and 76.9%.
Step-by-step explanation:
The interpretation of a confidence interval of level x% means that we are x% sure that the interval contains the true mean of the population.
In this problem, we have that:
The population are all the cell phone users.
The 95% confidence interval is (73.1%, 76.9%).
Which of the following is an appropriate interpretation of the 95% confidence interval?
D. We can be 95% confident that the proportion of all cell phone users who use text messaging is between 73.1% and 76.9%.
It could only be scalene or isosceles ... an equilateral triangle has all 60 degree angles
Isosceles- 90-45-45 degrees
Scalene- 90-35-55 degrees
I'm sorry, but what digit is underlined?
Answer:
Step-by-step explanation:
9 * -9 * -1 =
-81 * -1 =
81 <===
In multiplying (or dividing), if the signs are the same, the result is positive
if the signs are different, the result is negative
these rules do not apply to addition or subtraction
Answer:
a.0.8664
b. 0.23753
c. 0.15866
Step-by-step explanation:
The comptroller takes a random sample of 36 of the account balances and calculates the standard deviation to be N42.00. If the actual mean (1) of the account balances is N175.00, what is the probability that the sample mean would be between
a. N164.50 and N185.50?
b. greater than N180.00?
c. less than N168.00?
We solve the above question using z score formula
z = (x-μ)/σ/√n where
x is the raw score,
μ is the population mean = N175
σ is the population standard deviation = N42
n is random number of sample = 36
a. Between N164.50 and N185.50?
For x = N 164.50
z = 164.50 - 175/42 /√36
z = -1.5
Probability value from Z-Table:
P(x = 164.50) = 0.066807
For x = N185.50
z = 185.50 - 175/42 /√36
z =1.5
Probability value from Z-Table:
P(x=185.50) = 0.93319
Hence:
P(x = 185.50) - P(x =164.50)
= 0.93319 - 0.066807
= 0.866383
Approximately = 0.8664
b. greater than N180.00?
x > N 180
Hence:
z = 180 - 175/42 /√36
z = 5/42/6
z = 5/7
= 0.71429
Probability value from Z-Table:
P(x<180) = 0.76247
P(x>180) = 1 - P(x<180) = 0.23753
c. less than N168.00?
x < N168.
z = 168 - 175/42 /√36
z = -7/42/6
z = -7/7
z = -1
Probability value from Z-Table:
P(x<168) = 0.15866