Common factor of 12/15

Which One Doesn't Belong (WODB)

mina [271]

ANSWER:

[i] 4 × 10.56 = 42.2

[ii] 5 × 0.432 = 2.16 (not 2.18)

So, Correct choice - [B]

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.

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

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

$X - 61 = 2.96*8$

$X = 84.68$

The minimum score for an A is 84.68.

8 0

3 years ago

Theoretical probability P(rolling a 2) P(rolling a 5)

zysi [14]

Answer:

yes indeed..... (wdm? u never finished the question)

Step-by-step explanation:

8 0

3 years ago

ANSWER QUESTION A. ANSWER QUESTION B

RUDIKE [14]

Answer:

a. There is a causation relationship and positive trend between number of hours on homework and higher test scores.

b. 76

Step-by-step explanation:

a. Since the dots all follow a linear progression and increase closely together this is a positive trend and likely a causation relationship.

b. y=7x+41 can predict a test score. x is the number of hours, so if 5 if the number of hours then y=7(5)+41 = 35+41=76

6 0

3 years ago

Read 2 more answers

Dr. E. Quation says the Infant Mortality Rate of Korea shown by the expression; 7(m + 3) - 2. Is equal to his criminal success r

GarryVolchara [31]

Answer:

The infant mortality rate in Korea based on equality provided is:

1.8

Step-by-step explanation:

Since the text mentions that the infant mortality rate in Korea is equal to the criminal success rate, the two expressions must equalize and clear the variable m, which is the rate in each of the expressions:

7 (m + 3) - 2 = 8m + 17.2
7m + 21 - 2 = 8m + 17.2
7m + 19 = 8m + 17.2
19 - 17.2 = 8m - 7m
1.8 = m

As you can see, once the equality of the expressions is solved, a rate of 1.8 is obtained.

6 0

3 years ago