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2 years ago

What is the mean number of hours volunteered by students in the survey

Mathematics

2 answers:

Svetach [21]2 years ago

5 0

Answer: Where is the survey

Step-by-step explanation:

Tems11 [23]2 years ago

3 0

Answer:

I don't see the survey but I'll tell you how to find the mean.

Step-by-step explanation:

You add up all of your numbers and then divide that sum by the number of numbers you have. That's how you find the mean. Hope this helps.

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Math help please will give brainliest

natulia [17]

The answer is C. go with it.

3 0

3 years ago

"A study of the amount of time it takes a mechanic to rebuild the transmission for a 2005 Chevrolet Cavalier shows that the mean

Arada [10]

Answer:

85.31% probability that their mean rebuild time exceeds 8.1 hours.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Central limit theorem:

The Central Limit Theorem estabilishes that, for a random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sample means with size n of at least 30 can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$

In this problem, we have that:

$\mu = 8.4, \sigma = 1.8, n = 40, s = \frac{1.8}{\sqrt{40}} = 0.2846$

If 40 mechanics are randomly selected, find the probability that their mean rebuild time exceeds 8.1 hours.

This is 1 subtracted by the pvalue of Z when X = 8.1. So

$Z = \frac{X - \mu}{\sigma}$

By the Central Limit Theorem

$Z = \frac{X - \mu}{s}$

$Z = \frac{8.1 - 8.4}{0.2846}$

$Z = -1.05$

$Z = -1.05$ has a pvalue of 0.1469

1 - 0.1469 = 0.8531

85.31% probability that their mean rebuild time exceeds 8.1 hours.

4 0

3 years ago

Write an equation that is perpendicular to and 3x+y=3 whose y-intercept 5. Anyone please help me, no link just explain how to do

Liula [17]

Answer:

$y = \frac{1}{3}x + 5$

Step-by-step explanation:

By definition, two lines are perpendicular if and only if their slopes are negative reciprocals of each other: $m = - \frac{1}{m_{2} }$ , or equivalently, $m_{1} * m_{2} = -1$ .

Given our linear equation 3x + y = 3 (or y = -3x + 3):

We can find the equation of the line (with a y-intercept of 5) that is perpendicular to y = -3x + 3 by determining the negative reciprocal of its slope, -3, which is $\frac{1}{3}$ .