The value of the z statistic for the considered data is given by: Option A: -3.87 approximately.
<h3>How to find the z score (z statistic) for the sample mean?</h3>
If we're given that:
- Sample mean =
- Sample size = n
- Population mean =
- Sample standard deviation = s
Then, we get:
If the sample standard deviation is not given, then we can estimate it(in some cases) by:
where 
population standard deviation
For this case, we're specified that:
- Sample mean = = 2.3
- Sample size = n = 15
- Population mean = = 2.7
- Population standard deviation = = 0.4
Thus, the value of the z-statistic is evaluated as:
Thus, the value of the z statistic for the considered data is given by: Option A: -3.87 approximately.
Learn more about z statistic here:
brainly.com/question/27003351
So we are given the mean and the s.d.. The mean is 100 and the sd is 15 and we are trying the select a random person who has an I.Q. of over 126. So our first step is to use our z-score equation:
z = x - mean/s.d.
where x is our I.Q. we are looking for
So we plug in our numbers and we get:
126-100/15 = 1.73333
Next we look at our z-score table for our P-value and I got 0.9582
Since we are looking for a person who has an I.Q. higher than 126, we do 1 - P. So we get
1 - 0.9582 = 0.0418
Since they are asking for the probability, we multiply our P-value by 100, and we get
0.0418 * 100 = 4.18%
And our answer is
4.18% that a randomly selected person has an I.Q. above 126
Hopes this helps!
Set up a proprtion and cross multiply.
18/7.5=22/4x+1
7.5×22=18 (4x+1)
165=72x+18
147=72x
x=2.04
Step-by-step explanation:
ans will be 12 X will be the ans
Answer:
0.500 hour
Step-by-step explanation:
Givens
<em><u>Distance</u></em>
- Total Distance on the highway = 3hr * 60 miles / hr = 180 miles
- Distance in the city = 20 miles
- Total Distance = 180 + 20 = 200 miles
<em><u>Time</u></em>
- Time on the highway = 3 hours
- Time in the city = x
Formula
d /t = r
Solution
- Average rate = 57.14
- Total Distance / Total Time = average rate
- 200 / (3 + x) = 57.14 Multiply both sides by 3 + x
- 200 = 57.14 * (3 + x) Remove the brackets
- 200 = 57.14*3 + 57.14x Multiply the factors on the right
- 200 = 171.42 + 57.14x Subtract 171.42 from both sides.
- 200 - 171.42 = 171.42 - 171.42 + 57.14x So the subtraction
- 28.58 = 57.14x Divide by 57.14
- 28.57/57.14 = x
- x = 0.500 hour Answer
