HELP ME ASAP URGENT!!!

Mathematics

1 answer:

LenaWriter [7]3 years ago

8 0

The answer is infinite solutions linear equations always have infinite solutions when solving them

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What is the solution to 3x + 7 < 19? x < 4 x > 4 x < 12 x > 12

Lana71 [14]

X<12 with a line underneath.

6 0

3 years ago

Read 2 more answers

The school that molly goes to is selling tickets to a choral performance. On the first day of ticket sales the school sold 6 sen

krek1111 [17]

The cost of a senior citizen ticket is $15 and the cost of a student ticket is $12.

How did I get this?
We know that 6 citizen tickets and 7 student stickers sold for $174 the first day. And 10 citizen tickets and 14 student tickets sold for $318 the second day.

1. create two equations out of this: C= citizen cost per ticket and S = student cost per ticket.

6C + 7S = $174
10C + 14S = $318

2. Use process of elimination. Multiply the first equation by 2 because we want two variables to cancel out.

-12C - 14S = -$348
10C + 14S = $318
Combine like terms.

-2C = $30
Divide by -2 on both sides. The left side cancels out.

C = $30/-2
C = -$15 (In this case the negative doesn't matter)

C = $15 (cost of senior citizen ticket)

Plug the value of C into any of the two equations so we can get the value of S.

6($15) + 7S = $174
Distribute the 6 into the parenthesis.

$90 + 7S = $174
Subtract both sides by $90 and the left side will cancel out.

7S = $84
Divide both sides by 7.
S = $12

Student ticket: $12
Senior citizen ticket: $15

5 0

3 years ago

A math professor notices that scores from a recent exam are normally distributed with a mean of 61 and a standard deviation of 8

Alexeev081 [22]

Answer:

a) 25% of the students exam scores fall below 55.6.

b) The minimum score for an A is 84.68.

Step-by-step explanation:

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score 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 p-value, we get the probability that the value of the measure is greater than X.

Mean of 61 and a standard deviation of 8.

This means that $\mu = 61, \sigma = 8$

(a) What score do 25% of the students exam scores fall below?

Below the 25th percentile, which is X when Z has a p-value of 0.25, that is, X when Z = -0.675.

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

$-0.675 = \frac{X - 61}{8}$

$X - 61 = -0.675*8$

$X = 55.6$

25% of the students exam scores fall below 55.6.

(b) Suppose the professor decides to grade on a curve. If the professor wants 0.15% of the students to get an A, what is the minimum score for an A?

This is the 100 - 0.15 = 99.85th percentile, which is X when Z has a p-value of 0.9985. So X when Z = 2.96.

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

$2.96 = \frac{X - 61}{8}$