The answer is b = 3. you subtract 24 from bothe sides and then divide by 2.
1.What is the mean of the given distribution, and which type of skew does it exhibit? {4.5, 3, 1, 2, 4, 3, 6, 4.5, 4, 5, 2, 1, 3
marysya [2.9K]
Mean = (4.5 + 3 + 1 + 2 + 4 + 3 + 6 + 4.5 + 4 + 5 + 2 + 1 + 3 + 4 + 3 + 2)/16 = 50/16 = 3.125
The data set arranged in order is 1, 1, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4.5, 4.5, 5, 6
The mean is relatively in the middle, therefore if exhibits center skewness.
Answer: This’s the answer for your question 12.405
Answer:
Step-by-step explanation:
We would set up the hypothesis test. This is a test of a single population mean since we are dealing with mean
For the null hypothesis,
µ = 12
For the alternative hypothesis,
µ < 12
Since the population standard deviation is given, z score would be determined from the normal distribution table. The formula is
z = (x - µ)/(σ/√n)
Where
x = sample mean
µ = population mean
σ = population standard deviation
n = number of samples
From the information given,
µ = 12 minutes
x = 8 minutes
σ = 12 minutes
n = 36
z = (8 - 12)/(12/√36) = - 4/2 = - 2
Test statistic = - 2
We need to 'standardise' the value of X = 14.4 by first calculating the z-score then look up on the z-table for the p-value (which is the probability)
The formula for z-score:
z = (X-μ) ÷ σ
Where
X = 14.4
μ = the average mean = 18
σ = the standard deviation = 1.2
Substitute these value into the formula
z-score = (14.4 - 18) ÷ 1..2 = -3
We are looking to find P(Z < -3)
The table attached conveniently gives us the value of P(Z < -3) but if you only have the table that read p-value to the left of positive z, then the trick is to do:
1 - P(Z<3)
From the table
P(Z < -3) = 0.0013
The probability of the runners have times less than 14.4 secs is 0.0013 = 0.13%