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3 years ago

Use rounding to estimate

Mathematics

2 answers:

poizon [28]3 years ago

7 0

3. my answer I got was 6.53. I think it rounds to 7

Artyom0805 [142]3 years ago

6 0

First use addition, add everything up so...
First question is asking: 2.57+0.14= 2.71. To round it, see the 7, is it greater than 5? If yes then the 2 will be change to 3. So it's 3 as your answer.

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25+5 Times blank equals 35

mezya [45]

Let x = blank

25 + 5x = 35

5x = 35 - 25

5x = 10

x = 10/5

x = 2

Done!

6 0

2 years ago

Which of the following sequences is an arithmetic sequence? 1, 2, 4, 8, 18, ... 10, 12, 14, 16, 18, ... 200, 100, 50, 25, ... 4,

Leni [432]

The sequence 10, 12, 14, 16, 18, ... is an arithmetic sequence, with the common difference being 2.

6 0

3 years ago

Hugh says that “one less than four times a number” can be written as two expressions: 1 - 4n and 4n - 1. Why is Hugh incorrect?

Basile [38]

Answer:

N times 4-1

Step-by-step explanation:

4 times number is not a squared number where you multiply- the number

by it's self and then you subtract 1

8 0

3 years ago

What interest rate, to the nearest tenth of a percent, that is required for an investment subject to continuous compounding to i

Sunny_sXe [5.5K]

Answer:

It will take an interest rate of 8.1% to get 150% of the initial investment in just 5 years.

Step-by-step explanation:

Use the formula for continuous compounding

$X(t) = Pe^{rt}$

where r stands for the (annual) interest rate, t for time in years, P for the initial principal (investment) and X is the amount after t years.

(this formula can be beautifully derived from just basic considerations, btw)

We are given t=5, and percent increase on the initial P, so we can solve for r

$X(5) = 1.5P=Pe^{r\cdot5}\\1.5=e^{r\cdot5}\\\ln 1.5=\ln e ^{5r}\\\ln 1.5=5r\\r = \frac{\ln 1.5}{5}=0.081\rightarrow 8.1\%$

It will take an interest rate of 8.1% to get 150% of the initial investment in just 5 years.

5 0

3 years ago

The mean life of a television set is 119119 months with a standard deviation of 1414 months. If a sample of 7474 televisions is

Pepsi [2]

Answer:

0.5034 = 50.34% probability that the sample mean would differ from the true mean by less than 1.1 months

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 can be 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 random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sample means with size n of at least 30 can be approximated to a normal distribution with mean

In this problem, we have that:

$\mu = 119, \sigma = 14, n = 74, s = \frac{14}{\sqrt{74}} = 1.6275$