Answer:
We accept the null hypothesis and reject the alternate hypothesis. There is no evidence to conclude that the population mean is greater than 29. The population mean is less than or equal to 29.
Step-by-step explanation:
We are given the following in the question:
Population mean, μ = 29
Sample mean,
= 30
Sample size, n = 47
Alpha, α = 0.05
Population standard deviation, σ = 5
First, we design the null and the alternate hypothesis
a) This is a one-tailed test because the alternate hypothesis is in greater than direction.
We use One-tailed z test to perform this hypothesis.
b)
, we reject the null hypothesis and accept the alternate hypothesis and if
, we accept the null hypothesis and reject the alternate hypothesis.
c) Formula:
Putting all the values, we have
d) Now,
Since,
We accept the null hypothesis and reject the alternate hypothesis. There is no evidence to conclude that the population mean is greater than 29. The population mean is less than or equal to 29.
e) P-value is 0.0853
On the basis of p value we again accept the null hypothesis.
Population = 135 students
Mean score = 72.3
Standard deviation of the scores = 6.5
Part (a): Students from 2SD and 3SD above the mean
2SD below and above the mean includes 95% of the population while 3SD includes 99.7% of the population.
95% of population = 0.95*135 ≈ 129 students
99.7% of population = 0.997*135 ≈ 135 students
Therefore, number of students from 2SD to 3SD above and below the bean = 135 - 129 = 6 students.
In this regard, Students between 2SD and 3SD above the mean = 6/2 = 3 students
Part (b): Students who scored between 65.8 and 72.3
The first step is to calculate Z values
That is,
Z = (mean-X)/SD
Z at 65.8 = (72.3-65.8)/6.5 = 1
Z at 72.3 = (72.3-72.3)/6.5 = 0
Second step is to find the percentages at the Z values from Z table.
That is,
Percentage of population at Z(65.8) = 0.8413 = 84.13%
Percentage of population at (Z(72.3) = 0.5 = 50%
Third step is to calculate number of students at each percentage.
That is,
At 84.13%, number of students = 0.8413*135 ≈ 114
At 50%, number of students = 0.5*135 ≈ 68
Therefore, students who scored between 65.8 and 72.3 = 114-68 = 46 students
Answer:
3x+5
Step-by-step explanation:
Let number =X
So
Five more than 3 times a number
3x+5
9 decimeters. deci = 0.1
9 *0.1 meters.
0.9 meters
9 decimeters = 0.9 meters.
Answer:
4
Step-by-step explanation:
since it's all addition, we can remove the parentheses

Now we combine like terms


We subtract both sides by 12 to get,

now we divide both sides by 11

