Answer:
a)
And we want the probability from 0 to two deviations above the mean and we got 95/2 = 47.5 %
b)
So one deviation below the mean we have: (100-68)/2 = 16%
c)
For this case below 2 deviation from the mean we have 2.5% and above 1 deviation from the mean we got 16% and then the percentage between -2 and 1 deviation above the mean we got: (100-16-2.5)% = 81.5%
Step-by-step explanation:
For this case we have a random variable with the following parameters:
From the empirical rule we know that within one deviation from the mean we have 68% of the values, within two deviations we have 95% and within 3 deviations we have 99.7% of the data.
We want to find the following probability:
We can find the number of deviation from the mean with the z score formula:
And replacing we got
And we want the probability from 0 to two deviations above the mean and we got 95/2 = 47.5 %
For the second case:
So one deviation below the mean we have: (100-68)/2 = 16%
For the third case:
And replacing we got:
For this case below 2 deviation from the mean we have 2.5% and above 1 deviation from the mean we got 16% and then the percentage between -2 and 1 deviation above the mean we got: (100-16-2.5)% = 81.5%
Answer:
4 - ( 3x - 8 ) = 21
break the bracket first ,it gives : 4 - 3x + 8 = 21
12 - 3x = 21
- 3x = 21 - 12
- 3x = 9
-x = 9/3
-x = 3
X = - 3
[ check if the answer is correct, put -3 instead of X in the above equation ! we get 4 - { 3(-3) - 8 } = 21
4 - { - 9 - 8 } = 21
4 - { - 17 } = 21
break the bracket, minus and minus will multiply and will become plus , so we have 4 + 17 = 21 , hence 21 = 21 ! therefore X = -3
Answer:
The two-tailed P value equals 0.2308
By conventional criteria, this difference is considered to be not statistically significant.
Step-by-step explanation:
Given is a random sample of 10 single mothers
the ages are given as
22, 17, 27, 20, 23, 19, 24, 18, 19, and 24 years
H0: Mean = 20
Ha: Mean not equals 20
(two tailed test at 5% significance level)
The hypothetical mean is 20.00
The actual mean is 21.30
The difference between these two values is 1.30
The 95% confidence interval of this difference:
From -0.99 to 3.59
t = 1.2851
df = 9
standard error = 1.012
The two-tailed P value equals 0.2308
By conventional criteria, this difference is considered to be not statistically significant.
Answer:
c
Step-by-step explanation:
Here's how this works:
Get everything together into one fraction by finding the LCD and doing the math. The LCD is sin(x) cos(x). Multiplying that in to each term looks like this:
In the first term, the cos(x)'s cancel out, and in the second term the sin(x)'s cancel out, leaving:
Put everything over the common denominator now:
Since , we will make that substitution:
We could separate that fraction into 2:
×
and
Therefore, the simplification is
sec(x)csc(x)
R=16
J=32
20+40(which is 20×2)=60
20-4=16
16×2=32