What is the solution set for the quadratic inequality x2

A community college has a math placement exam that has a mean of 65 and a standard deviation of 8.2. If a student takes the exam

Marat540 [252]

Answer:

The score that cuts off the bottom 2.5% is 48.93.

Step-by-step explanation:

When the distribution is normal, we use 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.

In this question, we have that:

$\mu = 65, \sigma = 8.2$

What is the score that cuts off the bottom 2.5%

This is X when Z has a pvalue of 0.025, so X when Z = -1.96.

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

$-1.96 = \frac{X - 65}{8.2}$

$X - 65 = -1.96*8.2$

$X = 48.93$

The score that cuts off the bottom 2.5% is 48.93.

8 0

3 years ago

Read 2 more answers

what is the equation of the line that passes through the points (-2,1) and (1,10)? a) 3x-y=-7 b)3x-y=-5 c)3x-y=5 d)x 3y=-5

Ber [7]

The answer is a.
Substitute (-2,1) and (1,10) into each answer. Only a is correct because you will get -7 from both points.

8 0

3 years ago

2/3(x+6)=-18 what is the value of x

sladkih [1.3K]

Answer:

x = -33

Step-by-step explanation:

2/3(x+6)=-18

Multiply each side by 3/2

3/2*2/3(x+6)=-18*3/2

x+6 = -27

Subtract 6 from each side

x +6-6 = -27-6

x = -33

4 0

3 years ago

Barron's reported that the average number of weeks an individual is unemployed is 17.5 weeks. Assume that for the population of

Olin [163]

Answer:

$P(16.5$

And using the normal standard table or excel we find the probability:

$P(-1.768< Z< 1.768) = P(Z$

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Solution to the problem

Let X the random variable that represent the avergae number of weeks an individual is unemployed of a population, and for this case we know the distribution for X is given by:

$X \sim N(17.5,4)$