43,785 to the nearest ten thousand

The vertex of this parabola is at (-3, -2). which of the following could be its equation?

professor190 [17]

Answer:

B

Since the vertex is (-3,-2) The x value should be +3

7 0

2 years ago

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A set of test scores is normally distributed with a mean of 130 and a standard deviation of 30 What score is necessary to reach

nlexa [21]

Answer:

A score of 150.25 is necessary to reach the 75th percentile.

Step-by-step explanation:

Problems of normal distributions can be 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.

A set of test scores is normally distributed with a mean of 130 and a standard deviation of 30.

This means that $\mu = 130, \sigma = 30$

What score is necessary to reach the 75th percentile?

This is X when Z has a pvalue of 0.75, so X when Z = 0.675.

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

$0.675 = \frac{X - 130}{30}$

$X - 130 = 0.675*30$

$X = 150.25$

A score of 150.25 is necessary to reach the 75th percentile.

7 0

2 years ago

Why is it 1/6, plz explain

Mkey [24]

On that chart on the top right does it only include population?

7 0

2 years ago

Find the order pairs for the x- and y- intercepts of the equation 2x-6y=24

dolphi86 [110]

The answer is going to be
x= 2,0
y= 0, -6

5 0

2 years ago

If 6 pipes fill a tank in 120 minutes, then 5 pipes can fill it in how many minutes

Marianna [84]

Answer:

It'll take 144 minutes for 5 pipes.

Step-by-step explanation:

${ \sf{6 \: pipes = 120 \: mins}} \\ { \sf{5 \: pipes = ( \frac{6}{5} \times 120) \: mins}} \\ \\ = { \sf{144 \: mins}}$

but practically, it seems to be abnormal. if 6 pipes take 120 mins, 5 pipes must takes a time greater than 120 mins cause amount of water flowing to the tank is decreasing.

But there is a possibility that pressure of water was increased for the case of five pipes, that's why it takes a time less than 120 mins. (t < 120)

5 0

2 years ago

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