Jessica sold 16 times more books than Josh together they sold 238 books how many did each one of them sell

3 less than the quotient of 20 and x

UkoKoshka [18]

It would be (20/x) -3

3 0

3 years ago

In ΔIJK, j = 540 inches, ∠I=54° and ∠J=69°. Find the area of ΔIJK, to the nearest square inch.

xenn [34]

Answer:

105963

Step-by-step explanation: delta math

3 0

3 years ago

Simplify by dividing negative three over eight divided by five over nine.

goblinko [34]

Answer:

$\frac{-27}{40}$

Step-by-step explanation:

First we need to write in correct form :

$\frac{-3}{8}:\frac{5}{9}$

We know how to divide fractions. If we can divide numerator by numerator, denominator by denominator, we just do it. In this example we can not do that.

So, we rewrite first fraction and multiply by reciprocal second ( numerator and denominator change place)

$\frac{-3}{8} *\frac{9}{5}$

Now, multiply numerator by numerator, denominator by denominator :

$\frac{-27}{40}$

8 0

3 years ago

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Dylan Rieder is a statistics student investigating whether athletes have better balance than non-athletes for a thesis project.

Kobotan [32]

Answer:

$t=\frac{(3.7-4.1)-0}{\sqrt{\frac{1.1^2}{32}+\frac{1.3^2}{45}}}}=-1.457$

$p_v =P(t_{75}$

Comparing the p value with a significance level for example $\alpha=0.01$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can't say that the population mean for the athletes is significantly lower than the population mean for non athletes.

Step-by-step explanation:

Data given and notation

$\bar X_{A}=3.7$ represent the mean for athletes

$\bar X_{NA}=4.1$ represent the mean for non athletes

$s_{A}=1.1$ represent the sample standard deviation for athletes

$s_{NA}=1.3$ represent the sample standard deviation for non athletes

$n_{A}=32$ sample size for the group 2

$n_{NA}=45$ sample size for the group 2

$\alpha=0.01$ Significance level provided

t would represent the statistic (variable of interest)

Concepts and formulas to use

We need to conduct a hypothesis in order to check if the population mean for athletes is lower than the population mean for non athletes, the system of hypothesis would be:

Null hypothesis: $\mu_{A}-\mu_{NA}\geq 0$

Alternative hypothesis: $\mu_{A} - \mu_{NA}< 0$

We don't have the population standard deviation's, we can apply a t test to compare means, and the statistic is given by:

$t=\frac{(\bar X_{A}-\bar X_{NA})-\Delta}{\sqrt{\frac{s^2_{A}}{n_{A}}+\frac{s^2_{NA}}{n_{NA}}}}$ (1)

t-test: Is used to compare group means. Is one of the most common tests and is used to determine whether the means of two groups are equal to each other.

With the info given we can replace in formula (1) like this:

$t=\frac{(3.7-4.1)-0}{\sqrt{\frac{1.1^2}{32}+\frac{1.3^2}{45}}}}=-1.457$

P value

We need to find first the degrees of freedom given by:

$df=n_A +n_{NA}-2=32+45-2=75$

Since is a one left tailed test the p value would be:

$p_v =P(t_{75}$

Comparing the p value with a significance level for example $\alpha=0.01$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can't say that the population mean for the athletes is significantly lower than the population mean for non athletes.

5 0

3 years ago

Write the word sentence as an inequality. Then solve the inequality.

vladimir2022 [97]

Answer:

The inequality is 6x ≥ -24

The solution of this inequality is {x : x ∈ R, x ≥ -4} ⇒ [-4, ∞)

Step-by-step explanation:

In the inequality not more than means ≤

In the inequality at least means ≥

Let us solve the question

∵ Six times a number x means 6 × x = 6x

∵ At least means ≥

∴ Six times a number x is at least -24 is 6x ≥ -24

∴ The inequality is 6x ≥ -24

Now we will find the solution of the inequality

∵ 6x ≥ -24

→ Divide both sides by 6

∵ $\frac{6x}{6}$ ≥ $\frac{-24}{6}$

∴ x ≥ -4

∴ The solution of this inequality is {x : x ∈ R, x ≥ -4} ⇒ [-4, ∞)

6 0

3 years ago

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