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3 years ago

The average of the first five multiple of 7 is

Mathematics

1 answer:

Black_prince [1.1K]3 years ago

7 0

Answer:

b. 21

Step-by-step explanation:

The first five mutiples of 7 are: 7, 14, 21, 28, 35. You can get these by multiplying 7 to any integer.

7x1 = 7
7x2 = 14
7x3 = 21
7x4 = 28
7x5 = 35

In order to get the average of these numbers, you have to add them and divide the sum to the total number of multiples.

Let's add first.

7+14+21+28+35 = 105

Let's divided 105 by 5, which is the number of the multiples of 7.

105÷5 = 21

The answer is 21.

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Jenny washed dishes 4 times as many as her brother last month. Her brother washed dishes 8 times. Jenny said she could multiply

Julli [10]

Jenny is incorrect in her calculation.

For every time that Jenny's brother washed dishes, Jenny washed dishes 4 times. This tells that the the times they washed dishes occur in the ratio 4 :1. If Jenny's brother washed dishes 8 times, Jenny has to have washed dishes $4\times 8=32$ times. The way Jenny's is doing the calculation implies that his brother washed dishes $3*\times 8 =24$ times. He calculation yields a wrong result.

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3 years ago

a survey amony freshman at a certain university revealed that the number of hours spent studying the week before final exams was

Marat540 [252]

Answer:

Probability that the average time spent studying for the sample was between 29 and 30 hours studying is 0.0321.

Step-by-step explanation:

We are given that the number of hours spent studying the week before final exams was normally distributed with mean 25 and standard deviation 15.

A sample of 36 students was selected.

Let $\bar X$ = sample average time spent studying

The z-score probability distribution for sample mean is given by;

Z = $\frac{ \bar X-\mu}{\frac{\sigma}{\sqrt{n} } }} }$ ~ N(0,1)

where, $\mu$ = population mean hours spent studying = 25 hours

$\sigma$ = standard deviation = 15 hours

n = sample of students = 36

The Z-score measures how many standard deviations the measure is away from the mean. After finding the Z-score, we look at the z-score table and find the p-value (area) 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.

Now, Probability that the average time spent studying for the sample was between 29 and 30 hours studying is given by = P(29 hours < $\bar X$ < 30 hours)

P(29 hours < $\bar X$ < 30 hours) = P( $\bar X$ < 30 hours) - P( $\bar X$ $\leq$ 29 hours)

P( $\bar X$ < 30 hours) = P( $\frac{ \bar X-\mu}{\frac{\sigma}{\sqrt{n} } }} }$ < $\frac{ 30-25}{\frac{15}{\sqrt{36} } }} }$ ) = P(Z < 2) = 0.97725

P( $\bar X$ $\leq$ 29 hours) = P( $\frac{ \bar X-\mu}{\frac{\sigma}{\sqrt{n} } }} }$ $\leq$ $\frac{ 29-25}{\frac{15}{\sqrt{36} } }} }$ ) = P(Z $\leq$ 1.60) = 0.94520

So, in the z table the P(Z $\leq$ x) or P(Z < x) is given. So, the above probability is calculated by looking at the value of x = 2 and x = 1.60 in the z table which has an area of 0.97725 and 0.94520 respectively.

Therefore, P(29 hours < $\bar X$ < 30 hours) = 0.97725 - 0.94520 = 0.0321

Hence, the probability that the average time spent studying for the sample was between 29 and 30 hours studying is 0.0321.

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3 years ago

-2(11-12x)= -4(1-6x)

GalinKa [24]

The given equation -2(11 - 12x) = -4(1 - 6x) has infinite solutions

Solution:

Given that we have to solve the given expression

Given expression is:

-2(11 - 12x) = -4(1- 6x)

We have to use distributive property to solve the given expression

The distributive property lets you multiply a sum by multiplying each addend separately and then add the products.

Which means,

a(b + c) = ab + ac

Apply this in given expression

-2(11 - 12x) = -4(1-6x)

-22 + 24x = -4 + 24x

When both sides of the equation are simplified, the coefficients are the same, then infinite number of solutions occur

If we end up with the same term on both sides of the equal sign, such as 24x = 24x, then we have infinite solutions

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3 years ago

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Andrej [43]

D the Escrow Account

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3 years ago

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If function g(x) = x2 + 2 is a transformation of the quadratic parent function, f(x) = x2, where is the y-intercept of function

Sonbull [250]

Answer:

The y-intercept of function g located at (0,2)

Step-by-step explanation:

Function : $g(x)=x^2+2$

g(x) is a transformation of the quadratic parent function

We are supposed to find the where is the y-intercept of function g located

y intercept = the y-coordinate of a point where a line, curve, or surface intersects the y-axis i.e. x =0

So, substitute x = 0 in function

g(x)=x^2+2

g(0)=0^2+2

g(0)=2

So,(x,y)=(0,2)

So, The y-intercept of function g located at (0,2)

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3 years ago

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