Simplify the difference. (–7x – 5x^4 + 5) – (–7x^4 – 5 – 9x)
1 answer:
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Answer:
The probability of the sample mean foot length less than 23 cm is 0.120
Step-by-step explanation:
* Lets explain the information in the problem
- The eighth-graders asked to measure the length of their right foot at
the beginning of the school year, as part of a science project
- The foot length is approximately Normally distributed, with a mean of
23.4 cm
∴ μ = 23.4 cm
- The standard deviation of 1.7
∴ σ = 1.7 cm
- 25 eighth-graders from this population are randomly selected
∴ n = 25
- To find the probability of the sample mean foot length less than 23
∴ The sample mean x = 23, find the standard deviation σx
- The rule to find σx is σx = σ/√n
∵ σ = 1.7 and n = 25
∴ σx = 1.7/√25 = 1.7/5 = 0.34
- Now lets find the z-score using the rule z-score = (x - μ)/σx
∵ x = 23 , μ = 23.4 , σx = 0.34
∴ z-score = (23 - 23.4)/0.34 = -1.17647 ≅ -1.18
- Use the table of the normal distribution to find P(x < 23)
- We will search in the raw of -1.1 and look to the column of 0.08
∴ P(X < 23) = 0.119 ≅ 0.120
* The probability of the sample mean foot length less than 23 cm is 0.120
Answer:
The speed of the cars is
Step-by-step explanation:
First we must first have the clear concept that or
Our question is the speed of the cars then the variable to clear will be s.
Let's raise the equation for each car taking into account that we have the following data:
Car 1: ,
and
Car 1: ,
and
The two cars travel the same distance so we will raise the distance formula for each car and then match them.
<em>Car 1</em>
<em>Car 2</em>
The speed of the cars is 32 km/hr