Write an equation of the line that passes through (2,-3) and is perpendicular to the line y=-2x-3

A sample size 25 is picked up at random from a population which is normally

Margarita [4]

Answer:

a) P(X < 99) = 0.2033.

b) P(98 < X < 100) = 0.4525

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

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.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

Mean of 100 and variance of 36.

This means that $\mu = 100, \sigma = \sqrt{36} = 6$

Sample of 25:

This means that $n = 25, s = \frac{6}{\sqrt{25}} = 1.2$

(a) P(X<99)

This is the pvalue of Z when X = 99. So

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

By the Central Limit Theorem

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

$Z = \frac{99 - 100}{1.2}$

$Z = -0.83$

$Z = -0.83$ has a pvalue of 0.2033. So

P(X < 99) = 0.2033.

b) P(98 < X < 100)

This is the pvalue of Z when X = 100 subtracted by the pvalue of Z when X = 98. So

X = 100

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

$Z = \frac{100 - 100}{1.2}$

$Z = 0$

$Z = 0$ has a pvalue of 0.5

X = 98

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

$Z = \frac{98 - 100}{1.2}$

$Z = -1.67$

$Z = -1.67$ has a pvalue of 0.0475

0.5 - 0.0475 = 0.4525

So

P(98 < X < 100) = 0.4525

6 0

2 years ago

Serena estimates that she can paint 60 square feet of wall space every half-hour. Write an equation for the relationship with ti

Katarina [22]

Answer:

So, the relationship with i hours as the indecent variables would be

Serena can't paint 400 square feet of wall space of wall space in 3.5 hours.

Step-by-step explanation:

Since we have given that

Area that she can paint = 60 square feet

Time taken = half hour = 30 minutes = 0.5 hours

Using "Unitary method, we get that

In 0.5 hours, she can paint = 60 square feet

In 1 hour, she can paint =

In i hours, she can paint =

Let the total area she can paint be 'y'.

So, the relationship with i hours as the indecent variables would be

Now, Can Serena paint 400 square feet of wall space i. 3.5 hours

We put y = 400 and i = 3.5 hours to check whether it is equal or not.

Hence, Serena can't paint 400 square feet of wall space of wall space in 3.5 hours.

6 0

3 years ago

Read 2 more answers

A school goes through 10 gallons of milk in 3 days.

Akimi4 [234]

G = gallons d = days
10g = 3d
?g = 1d
1g = ?d
-------------
for gallons in a day, divide 10g = 3d by 3
d = 10/3 gallons
3 and 1/3 gallons in a day
---------------
for days per gallon, divide 10g = 3d by 10
g = 3/10 days
1 gallon lasts 3/10 of a day

3 0

2 years ago

Determine the slope-intercept form of the equation of the line parallel to y = x + 11 that passes through the point (–6, 2).

KATRIN_1 [288]

Answer:

y=4x+6

Step-by-step explanation:

4 0

3 years ago

In a recent survey, 18 people preferred milk, 29 people preferred coffee, and 13 people preferred juice as their primary drink f

marusya05 [52]

Answer: