Answer:
f(x) = 2x +1
Step-by-step explanation:
Apparently the ordered pairs are ...
(x, f(x)) = (1, 3), (2, 5), (3, 7), (4, 9)
We note that as x increases by 1, the value of f(x) increases by 2. The difference between f(x) and 2x is 3-2·1 = 1, so we have ...
f(x) -2x = 1
f(x) = 2x +1 . . . . . . add 2x
Answer:
b. Mean = 1.6 years, standard deviation - 0.92 years, shape: approximately Normal.
Step-by-step explanation:
Central Limit Theorem
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean and standard deviation
, the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean
and standard deviation
.
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
Subtraction of normal Variables:
When we subtract normal variables, the mean is the subtraction of the means, while the standard deviation is the square root of the sum of the variances.
A consumer group has determined that the distribution of life spans for gas ranges (stoves) has a mean of 15.0 years and a standard deviation of 4.2 years. Sample of 35:
This means that:
The distribution of life spans for electric ranges has a mean of 13.4 years and a standard deviation of 3.7 years. Sample of 40:
This means that:
Which of the following best describes the sampling distribution of the difference in mean life span of gas ranges and electric ranges?
Shape is approximately normal.
Mean:
Standard deviation:
So the correct answer is given by option b.