Heather is riding her bicycle. she takes 3 hours to ride 37.5 kilometers. what is her speed?

Suppose the test scores on an exam show a normal distribution with a mean of 82 and a standard deviation of

Zanzabum

Answer:

a) Between 74 and 90

b) 81.86% of the scores are between 78 and 90

Step-by-step explanation:

a) According to the Empirical Rule, in a normal distribution, 95% of the data are within 2 standard deviations of the mean. Therefore, the range that 95% of the scores fall in is between 82-4(2)=74 and 82+4(2)=90.

b) The percent of scores that are between 78 and 90 is: normalcdf(lower,upper,μ,σ) = normalcdf(78,90,82,4) = 0.8185946784 ≈ 0.8186, or about 81.86% of the scores.

5 0

3 years ago

An engineer is comparing voltages for two types of batteries (K and Q) using a sample of 37 type K batteries and a sample of 58

Olegator [25]

Answer:

Hypothesis Test states that we will accept null hypothesis.

Step-by-step explanation:

We are given that an engineer is comparing voltages for two types of batteries (K and Q).

where, $\mu_1$ = true mean voltage for type K batteries.

$\mu_2$ = true mean voltage for type Q batteries.

So, Null Hypothesis, $H_0$ : $\mu_1 = \mu_2$ {mean voltage for these two types of

batteries is same}

Alternate Hypothesis, $H_1$ : $\mu_1 \neq \mu_2$ {mean voltage for these two types of

batteries is different]

<em>The test statistics we use here will be :</em>

$\frac{(X_1bar-X_2bar) - (\mu_1 - \mu_2) }{s_p\sqrt{\frac{1}{n_1}+\frac{1}{n_2} } }$ follows $t_n__1 + n_2 -2$

where, $X_1bar$ = 8.54 and $X_2bar$ = 8.69

$s_1$ = 0.225 and $s_2$ = 0.725

$n_1$ = 37 and $n_2$ = 58

$s_p = \sqrt{\frac{(n_1-1)s_1^{2}+(n_2-1)s_2^{2} }{n_1+n_2-2} } = \sqrt{\frac{(37-1)0.225^{2}+(58-1)0.725^{2} }{37+58-2} }$ = 0.585 Here, we use t test statistics because we know nothing about population standard deviations.

Test statistics = $\frac{(8.54-8.69) - 0 }{0.585\sqrt{\frac{1}{37}+\frac{1}{58} } }$ follows $t_9_3$

= -1.219

<em>At 0.1 or 10% level of significance t table gives a critical value between (-1.671,-1.658) to (1.671,1.658) at 93 degree of freedom. Since our test statistics is more than the critical table value of t as -1.219 > (-1.671,-1.658) so we have insufficient evidence to reject null hypothesis.</em>

Therefore, we conclude that mean voltage for these two types of batteries is same.

6 0

3 years ago

HELP IN A TEST ILL GIVE BRAINLIEST

german

Answer:

Can u send a more clear pic

Step-by-step explanation:

thankyou

8 0

3 years ago

use an equation to write each fraction as multiple of unit fraction 1/6 + 1/6 + 1/6 + 1/6 + 1/6 how do you get to 5/6

weeeeeb [17]

Answer:

Equation: 1/6 + 1/6 + 1/6 + 1/6 + 1/6 = 5/6

Step-by-step explanation:

Unit means 1

Therefore a each 1/6 is the multiple unit of 5/6 because if we had all the 1/6 together, you get 5/6. There is 1 over 6 which you can tell that it is a unit fraction.

8 0

3 years ago

A car dealership has various combinations of vehicles in their car lot, all of which have an equally likely change of being sele

Effectus [21]

Answer:

The probability of a car being selected will be given by :the number of car required/ the total number of cars

Step-by-step explanation:

Probability is the likelihood of an event occurring.

This is given by : number of required outcome/number of possible outcome

7 0

3 years ago