All categories

2 years ago

Solve the linear expression 5(-3.4k-7)+(3k+21)

Mathematics

1 answer:

Marysya12 [62]2 years ago

4 0

I am just a middle-schooler, but like to answer, so I believe k is -1.

You might be interested in

The water works commission needs to know the mean household usage of water by the residents of a small town in gallons per day.

Alexeev081 [22]

Answer: 387

Step-by-step explanation:

Given : Standard deviation: $\sigma=2.3$

Margin of error : 0.15

Critical value for 80% confidence interval = 1.2816

Required minimum sample size : $n=(\dfrac{z_{\alpha/2}\cdot \sigma}{E})^2$

$\\\\=(\dfrac{1.2816\times2.3}{0.15})^2\\\\=386.16966144\approx387$

Hence, the minimum sample size required to estimate the mean usage of water = 387

4 0

2 years ago

Notice that the alternative hypothesis is a two-tailed test. Suppose ttest_ind method from scipy module is used to perform the t

Korvikt [17]

Answer:

The p-value of the test is 0.0512.

Step-by-step explanation:

The p-value of a test is well-defined as per the probability, [under the null hypothesis (H₀)], of attaining a result equivalent to or more extreme than what was the truly observed value of the test statistic.

In this case the output of the t-test_ind method from scipy module is provided as follows:

Output = (-1.99, 0.0512)

The first value within the parentheses is the test statistic value.

So the test statistic value is, -1.99.

And the second value within the parentheses is the p-value of the test.

So the p-value of the test is 0.0512.

6 0

2 years ago

For quality control purposes, a company that manufactures sim chips for cell/smart phones routinely takes samples from its pro

ololo11 [35]

Answer:

There is a 22.42% probability that a sample in this size has 2 imperfections.

Step-by-step explanation:

For each chip, there are only two possible outcomes. Either they are imperfect, or they are not.

This means that we can solve this problem using binomial distribution probability concepts.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.\pi^{x}.(1-\pi)^{n-x}$

In which $C_{n,x}$ is the number of different combinatios of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And $\pi$ is the probability of X happening.

In this problem

A success is a chip being imperfect. Suppose the average number of imperfections per 1000 sim chips is 3. So $\pi = \frac{3}{1000} = 0.003$ .

What is the probability that a sample this size (1000 chips) has 2 imperfections?

The sample has 1000 chips, wo $n = 1000$

We want P(X = 2).

$P(X = x) = C_{n,x}.\pi^{x}.(1-\pi)^{n-x}$

$P(X = 2) = C_{1000,2}.(0.003)^{2}.(0.997)^{998} = 0.2242$

There is a 22.42% probability that a sample in this size has 2 imperfections.

7 0

2 years ago

What is the first step to solve this equation : 11-3x=44

Zolol [24]

Answer:

Subtract 11 from both sides

Step-by-step explanation:

4 0

2 years ago

Read 2 more answers

Joe drove 100 miles from San Francisco to Gilroy and used 4 gallons of gas. How much gas should he expect to use for a 3000-mile

erma4kov [3.2K]

750 bc u dived 3000 by 4 bc 4 is per ever 100

3 0

2 years ago

Read 2 more answers