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3 years ago

14

The temperature outside in the morning was 15 degrees below zero. By lunchtime it was 25 degrees above zero. How many degreees d

id the temperature rise ?

1 answer:

Nikolay [14]3 years ago

6 0

It was -15, but it was then 25.

25 + 15 = 40

It rose 40 degrees.

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8(x-4)-10x simplify the equation

Citrus2011 [14]

Answer:

− 2x-32

Step-by-step explanation:

4 0

4 years ago

The equation shown below involves a perfect square trinomial. 4x2 + 20x + 25 = 7 Which of the following is a step in solving thi

fomenos

4 x^2 + 20 x + 25 = 7
Divide both sides by 4:
x^2 + 5 x + 25/4 = 7/4
Write the left-hand side as a square:
(x + 5/2)^2 = 7/4
Take the square root of both sides:
x + 5/2 = sqrt(7)/2 or x + 5/2 = -sqrt(7)/2
Subtract 5/2 from both sides:
x = sqrt(7)/2 - 5/2 or x + 5/2 = -sqrt(7)/2
Subtract 5/2 from both sides:
Answer: x = sqrt(7)/2 - 5/2 or x = -5/2 - sqrt(7)/2

3 0

4 years ago

In a large section of a statistics class, the points for the final exam are normally distributed, with a mean of 71 and a stan

kumpel [21]

Answer:

The lowest score on the final exam that would qualify a student for an A is 80.

The lowest score on the final exam that would qualify a student for a B is 74.68.

The lowest score on the final exam that would qualify a student for a C is 67.33.

The lowest score on the final exam that would qualify a student for a D is 62.

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.

Mean of 71 and a standard deviation of 7.

This means that $\mu = 71, \sigma = 7$

Grades are assigned such that the top 10% receive A's, the next 20% received B's, the middle 40% receive C's, the next 20% receive D's, and the bottom 10% receive F's.

This means that:

90th percentile and above: A

70th percentile and below 90th: B

30th percentile to the 70th percentile: C

10th percentile to the 30th: D

Lowest score for an A:

Top 10% receive A, which means that the lowest score that would qualify a student for an A is the 100 - 10 = 90th percentile, which is X when Z has a pvalue of 0.9, so X when Z = 1.28.

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

$1.28 = \frac{X - 71}{7}$

$X - 71 = 7*1.28$

$X = 80$

The lowest score on the final exam that would qualify a student for an A is 80.

Lowest score for a B:

70th percentile, which is X when Z has a pvalue of 0.7, so X when Z = 0.525.

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

$0.525 = \frac{X - 71}{7}$

$X - 71 = 7*0.525$

$X = 74.68$

The lowest score on the final exam that would qualify a student for a B is 74.68.

Lowest score for a C:

30th percentile, which is X when Z has a pvalue of 0.3, so X when Z = -0.525.

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

$-0.525 = \frac{X - 71}{7}$

$X - 71 = 7*(-0.525)$

$X = 67.33$

The lowest score on the final exam that would qualify a student for a C is 67.33.

Lowest score for a D:

10th percentile, which is X when Z has a pvalue of 0.1, so X when Z = -1.28.

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

$-1.28 = \frac{X - 71}{7}$

$X - 71 = 7*(-1.28)$

$X = 62$

The lowest score on the final exam that would qualify a student for a D is 62.

4 0

3 years ago

Learning Task No. 1 Randy, Manny and Jan put 3 As, 4 Bs and 5 Cs in the box. They will take turns in getting a letter from the b

wolverine [178]

Answer:

1. A = 3/12

B= 4/12

C = 5/12

2......

3. Randy

Step-by-step explanation:

3+4+5 = 12

therefore there are 12 letters in the box

we can say that there are 3/12 A's in the box and do the same for the remaining letters

question two does not make sense

3. the person who has the lowest fraction in value which is A

6 0

4 years ago

What is the correct factorization of 5!?

Oksi-84 [34.3K]

Answer:

B) 5 x 4 x 3 x 2 x 1

Step-by-step explanation:

When you see a ! directly next to a number (such as 5!), it means that you are multiplying starting from that number, and stepping down each time:

5! = 5 * 4 * 3 * 2 * 1

For example, take factoral 10: 10!

10! = 10 * 9 * 8 * 7 * 6 * 5 * 4 * 3 * 2 * 1 = 3,628,800

In this case, you are multiplying 5!.

5! = 5 * 4 * 3 * 2 * 1 = (20) * (6) * 1 = 120

5! = 120

4 0

4 years ago