Answer: 60.93 < μ < 69.07
Step-by-step explanation: The true mean of a set of data is between an interval of values with a percentage of precision, e.g., a <u>99% confidence interval</u> means we are 99% confident the true mean is between the lower and upper limits.
To find the interval, use
x±
z is z-score related to the % of confidence level
In this case, a 99% confidence interval is 2.576
x is sample mean
Calculating:
x = 65
65±
65±4.07
Confidence Interval: 60.93 < μ < 69.07
Meaning that we are 99% sure the population means is between 60.93 and 69.07.
Answer:
For a data set of N elements:
{x₁, x₂, ..., xₙ}
The mean is:
The mean absolute deviation is:
And the population standard deviation is:
In this case, our set has 5 elements, and the set is:
{2, 4, 6, 9, 14}
The mean of this set is:
The mean absolute deviation is:
And the population standard deviation is:
Answer: 8 hours
Step-by-step explanation:
Let x be the time taken by each person to paint the fence.
Given: Tom and Becky can paint Jim's fence together in 12 hours.
Since all people paint at the same rate, then we have the following equation ;-
Thus, the time taken by each person to paint the fence alone = 24 hours
Now, the time taken by all three paint together:-
Hence, it would take 8 hours if all three paint together.
In the secant secant theorem,
AP × BP = CP × DP
AP × 6 = 7 × 12
AP = 7 × 2 = 14
Answer: 14
