Answer:
The answer to the question is;
The probability that the resulting sample mean of nicotine content will be less than 0.89 is 0.1587 or 15.87 %.
Step-by-step explanation:
The mean of the distribution = 0.9 mg
The standard deviation of the sample = 0.1 mg
The size of the sample = 100
The mean of he sample = 0.89
The z score for sample mean is given by
where
X = Mean of the sample
μ = Mean of the population
σ = Standard deviation of the population
Therefore Z =
= -1
From the standard probabilities table we have the probability for a z value of -1.0 = 0.1587
Therefore the probability that the resulting sample mean will be less than 0.89 = 0.1587 That is the probability that the mean is will be less than 0.89 is 15.87 % probability.
Solving for the missing variable
Answer:
x = 13
Step-by-step explanation:
The area (A) of a trapezium is calculated as
A =
h (b₁ + b₂ )
where h is the perpendicular height and b₁, b₂ the parallel bases
Here A = 55, h = 5. b₁ = x, b₂ = 9, then
× 5 × (x + 9) = 55
2.5(x + 9) = 55 ( divide both sides by 2.5 )
x + 9 = 22 ( subtract 9 from both sides )
x = 13