How you save 6x-2=5x+29

It is said that sufferers of a cold virus experience symptoms for 7 days. However, the amount of time is actually a normally dis

AlexFokin [52]

Answer:

a) 0.18% of cold sufferers experience fewer than 4 days of symptoms

b) 64.40% of cold sufferers experience symptoms for between 7 and 10 days.

Step-by-step explanation:

Problems of normally distributed samples are 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.

In this problem, we have that:

$\mu = 7.5, \sigma = 1.2$

a. What proportion of cold sufferers experience fewer than 4 days of symptoms?

This is the pvalue of Z when X = 4. So

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

$Z = \frac{4 - 7.5}{1.2}$

$Z = -2.92$

$Z = -2.92$ has a pvalue of 0.0018.

So 0.18% of cold sufferers experience fewer than 4 days of symptoms.

b. What proportion of cold sufferers experience symptoms for between 7 and 10 days?

This is the pvalue of Z when X = 10 subtracted by the pvalue of Z when X = 7. So

X = 10

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

$Z = \frac{10 - 7.5}{1.2}$

$Z = 2.08$

$Z = 2.08$ has a pvalue of 0.9812.

X = 7

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

$Z = \frac{7 - 7.5}{1.2}$

$Z = -0.42$

$Z = -0.42$ has a pvalue of 0.3372.

So 0.9812 - 0.3372 = 0.644 = 64.40% of cold sufferers experience symptoms for between 7 and 10 days.

8 0

3 years ago

Explain how 3^7 + 2 must be an odd number

Firdavs [7]

It must be an odd number because 3^7 is also shown as:
3x3x3x3x3x3x3

Which equals:2,187

2,187 is an odd number because the last number is a 7 which is odd.

5 0

1 year ago

Sit in jail height 4 1/8 miles in the morning and 1 7/8 miles in the after noon. how many times as far did they hike in the morn

Ksenya-84 [330]

Skskskskskksksksksks shsvsk

7 0

3 years ago

"Express as a mixed numeral: 39/8" is a problem found in a fifth-grade arithmetic textbook. This problem is BEST solved through:

Scilla [17]

Answer:

c. an algorithm

Step-by-step explanation:

Most math problems are best solved using an algorithm. Certainly, converting numbers from one form to another is easily done that way.

_____

The integer part is the whole-number quotient of the division. The fractional part is the remainder divided by the denominator:

39/8 = 32/8 + 7/8 = 4 7/8

5 0

2 years ago

Two lines intersect at a point. The vertical angles formed are supplementary.

Nastasia [14]

we know that

<u>Vertical angles</u> are a pair of opposite and congruent angles formed by intersecting lines.

so

Let

x1---------> angle vertical 1

x2---------> angle vertical 2

x1=x2 ------> equation 1

in this problem

if the vertical angles formed are supplementary

that means that

x1+x2=180 ------> equation 2

substitute equation 1 in equation 2

x1+x1=180

2x1=180

x1=180/2

x1=90 degrees

therefore

<u>the answer is</u>

The vertical angles are right angles

8 0

3 years ago