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2 years ago

What is the value of 21 + 6² - (35 - 8) ×3? A. 90 B. 0 C. -24 D. -54

Mathematics

2 answers:

zalisa [80]2 years ago

7 0

Answer:

C. -24

Step-by-step explanation:

Hello!

To solve this we have to follow the order of PEMDAS

Parenthesis, exponents, multiplication and division, addition and subtraction

$21 + 6^{2} - (35 - 8) * 3$

Parenthesis first

$21 + 6^{2} - (27) * 3$

Exponents next

21 + 36 - 27 * 3

Multiplication and division from left to right

21 + 36 - 81

Addition and subtraction from left to right

57 - 81 = -24

The answer is C.-24

Hope this helps!

Oksana_A [137]2 years ago

4 0

Answer:

Step-by-step explanation:

$21+6^2-\left(35-8\right)\times \:3\\\\\mathrm{Follow\:the\:PEMDAS\:order\:of\:operations}\\\\\mathrm{Calculate\:within\:parentheses}\:\left(35-8\right)\::\quad 27\\\\=21+6^2-27\times \:3\\\\\mathrm{Calculate\:exponents}\:6^2\::\quad 36\\\\=21+36-27\times \:3\\\\\mathrm{Multiply\:and\:divide\:\left(left\:to\:right\right)}\:27\times \:3\::\quad 81\\\\=21+36-81\\\\\mathrm{Add\:and\:subtract\:\left(left\:to\:right\right)}\:21+36-81\::\quad -24\\\\=-24$

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PLEASE HELP ME ITS DUE TOMORROW!! THANKS!

leonid [27]

PART A
Change the fractions into improper fractions
pablo - rosa = 4 4/9 - 3 5/12
pablo - rosa = 40/9 - 41/12

Equalize the denominator of the fractions
I equalize them to 36. If the denominator 9 is multiplied by 4, so is the numerator. If the denominator 12 is multiplied by 3, so is the numerator.
pablo - rosa = 40/9 - 41/12
pablo - rosa = (40 × 4)/(9 × 4) - (41 × 3)/(12 × 3)
pablo - rosa = 160/36 - 123/36
pablo - rosa = 37/36

Change it to mixed fraction
pablo - rosa = 37/36
pablo - rosa = 1 1/36

Pablo has 1 1/36 quarts more than Rosa

PART B
Calculate the iced tea Pablo gave to Rosa
Change into proper fraction/improper fraction
iced tea given = 15% × 4 4/9
iced tea given = 15/100 × 40/9
iced tea given = 600/900
iced tea given = 2/3

Calculate Pablo's iced tea after giving
Pablo's = 40/9 - 2/3
Pablo's = 40/9 - (2 × 3)/(3×3)
Pablo's = 40/9 - 6/9
Pablo's = 34/9
Pablo's = 3 7/9

Calculate Rosa's iced tea
Rosa's = 41/12 + 2/3
Rosa's = 41/12 + (2 × 4)/(3 × 4)
Rosa's = 41/12 + 8/12
Rosa's = 49/12
Rosa's = 4 1/12

Pablo has 3 7/9 quarts and Rosa has 4 1/12 quarts

6 0

2 years ago

The amount of coffee that a filling machine puts into an 8-ounce jar is normally distributed with a mean of 8.2 ounces and a sta

nordsb [41]

Answer:

73.30% probability that the sampling error made in estimating the mean amount of coffee for all 8-ounce jars by the mean of a random sample of 100 jars will be at most 0.02 ounce

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 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.

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.

In this problem, we have that:

$\mu = 8.2, \sigma = 0.18, n = 100, s = \frac{0.18}{\sqrt{100}} = 0.018$

What is the probability that the sampling error made in estimating the mean amount of coffee for all 8-ounce jars by the mean of a random sample of 100 jars will be at most 0.02 ounce?

This is the pvalue of Z when X = 8.2 + 0.02 = 8.22 subtracted by the pvalue of Z when X = 8.2 - 0.02 = 8.18. So

X = 8.22

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

By the Central Limit Theorem

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

$Z = \frac{8.22 - 8.2}{0.018}$

$Z = 1.11$

$Z = 1.11$ has a pvalue of 0.8665

X = 8.18

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

$Z = \frac{8.18 - 8.2}{0.018}$

$Z = -1.11$

$Z = -1.11$ has a pvalue of 0.1335

0.8665 - 0.1335 = 0.7330

73.30% probability that the sampling error made in estimating the mean amount of coffee for all 8-ounce jars by the mean of a random sample of 100 jars will be at most 0.02 ounce

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3 years ago

Suppose that u⃗ =⟨−6,2⟩ and v⃗ =⟨−2,−6⟩. What is the angle between u⃗ and v⃗ , rounded to the nearest degree?

wlad13 [49]

Answer:

Ya'll ask the most complicated questions that never get answered just gooogle it dude

Step-by-step explanation:

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anzhelika [568]

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