What is the word for "numbers with square roots that are whole numbers"? I have no idea!

The "cold start ignition time" of an automobile engine is being investigated by a gasoline manufacturer. The following times, in

Nezavi [6.7K]

Answer:

1. Sample Mean = 2.50

2. Sample Variance = 1.35

3. Standard Deviation = 1.16

Step-by-step explanation:

Note: As this question is not complete, similar can be found on internet where following are asked to calculate and here I will calculate these as well.

1. Sample Mean.

2. Sample Variance.

3. Sample Standard Deviation.

So, for sample mean to calculate from the given data points. We need to apply to following formula to calculate sample mean.

Sample Mean = (X1 + X2 + .... + XN) divided by Total number of data points.

Sample Mean = (0.17 + 1.94 + 2.62 + 2.35 + 3.05 + 3.15 + 2.53 + 4.81 + 1.92) divided by (9).

Sample Mean = 2.50

Likewise, from the answer of sample mean we can calculate sample variance by following steps.

Solution:

1. Subtract the obtained mean from each of the data point given.

(0.17 - 2.50) = -2.33

(1.94 - 2.50) = -0.56

(2.62 - 2.50) = 0.12

(2.35 - 2.50) = -0.15

(3.05 - 2.50) = 0.55

(3.15 - 2.50) = 0.65

(2.53 - 2.50) = 0.03

(4.81 - 2.50) = 2.31

(1.92 - 2.50) = -0.58

2. Square each of the differences obtained in step 1.

$-2.33^{2}$ = 5.43

$-0.56^{2}$ = 0.31

$0.12^{2}$ = 0.01

$-0.15^{2}$ = 0.02

$0.55^{2}$ = 0.30

$0.65^{2}$ = 0.42

$0.03^{2}$ = 0.01

$2.31^{2}$ = 5.34

$-0.58^{2}$ = 0.34

3. Sum all of these squares.

(5.43 + 0.31 + 0.01 + 0.02 + 0.30 + 0.42 + 0.01 + 5.34 + 0.34) = 12.18

4. Divide 12.18 by (n-1), where n = 9.

Sample Variance = 12.18/9 = 1.35

Now, by using sample variance, we can calculate standard deviation with easy simple steps.

So, in order to find standard deviation, we just need to take the square root of sample variance that we have already calculated above.

Standard Deviation =  $\sqrt{1.35}$  = 1.16 

Good Luck!

6 0

3 years ago

a zoo has 19 more species of fish than birds. There are 152 species of fish at the zoo. How many species of birds does the zoo h

valentinak56 [21]

The equation would be 152 - 19 = X

X = 152 - 19

X = 133

There are 133 species of birds at the zoo

7 0

3 years ago

Help with #90 plz I need to figure it out

docker41 [41]

Answer:

14.4 inches to the nearest tenth.

Step-by-step explanation:

The square has area x^2 where x is the length of each side so:

x^2 = 13

x = √13.

The perimeter is the distance all around the square and this is 4x so we have the answer 4 *√13

14.422 inches.

4 0

3 years ago

The Acme Company manufactures widgets. The distribution of widget weights is bell-shaped. The widget weights have a mean of 37 o

just olya [345]

Answer:

a) 68 % will lie between 30 and 44 ounces

b) between 23 and 44 ounces will lie 81,5 %

Step-by-step explanation: See Annex

a) Normal Distribution N ( 37, 7)

The Empirical Rule establishes that 68 % of values will be at

μ ± 1 σ where μ is the mean and σ the standard deviation

Then: 37 - 7 = 30 and 37 + 7 = 44

68 % of the values will lie between 30 and 44 ounces

b) And between 23 and 44 we should find:

We have 95 % of values between

μ ± 2*σ

In our case to the left of the value (mean 0 ) and up to the value 23 we get 95/2 = 47,5 % and to the right of the value (mean 0 ) and up to 44 we half 68/2 = 34 %

Then between 23 and 44, we have 47,5 + 34 = 81,5 %

8 0

3 years ago

M 2 = a°, m 3 = b°, m 4 = a b a + b a - b (see picture)

Ket [755]

The answer is a+b. Since a triangle is equal to 180 degrees, and you know that angle 2 = a degrees and angle 3 = b degrees then you know that 180 degrees minus angle 2 and angle 3 = angle 1.

It is also known that angle 1 and angle 4 added together will be 180 degrees. Since before we already found out that angle 1 = 180 - angle2 + angle3, we know that angle4 = angle2+angle3

6 0

3 years ago