An Egyptian pyramid has a square base and four triangular faces. Use clay or Play-

9. To order books from an online site, the buyer must open an account. The buyer needs a username and a password.

slega [8]

Answer:

a)

i)208827064576

ii)62990928000

b)

i)28179280429056

ii)15214711438080

c)

i)899194740203776

ii)607681858331520

Step-by-step explanation:

a)

i)The alphabet consists of 26 letters.

For the first letter of the username there are 26 options.

For the second letter of the username there are 26 options.

For the third letter of the username there are 26 options.

For the fourth letter of the username there are 26 options.

For the fifth letter of the username there are 26 options.

For the sixth letter of the username there are 26 options.

For the seventh letter of the username there are 26 options.

For the eighth letter of the username there are 26 options.

To get the number of the possible usernames we multiply the number of options for each letter: 26 x 26 x 26 x 26 x 26 x 26 x 26 x 26 =26^8=208827064576

ii) If letter cannot be repeated.

For the first letter of the username there are 26 options.

For the second letter of the username there are only 25 options.

For the third letter of the username there are only 24 options.

For the fourth letter of the username there are only 23 options.

For the fifth letter of the username there are only 22 options.

For the sixth letter of the username there are only 21 options.

For the seventh letter of the username there are only 20 options.

For the eighth letter of the username there are only 19 options.

To get the number of the possible usernames we multiply the number of options for each letter: 26 x 25 x 24 x 23 x 22 x 21 x 20 x 19 =62990928000

b) 26 letters+10digits+12special characters=48 options

i) For the first letter of the password there are 48 options.

For the second letter of the password there are 48 options.

For the third letter of the password there are 48 options.

For the fourth letter of the password there are 48 options.

For the fifth letter of the password there are 48 options.

For the sixth letter of the password there are 48 options.

For the seventh letter of the password there are 48 options.

For the eighth letter of the password there are 48 options.

To get the number of the possible usernames we multiply the number of options for each letter: 48 x 48 x 48 x 48 x 48 x 48 x 48 x 48= 48^8=28179280429056

ii) If letter cannot be repeated.

For the first letter of the password there are 48 options.

For the second letter of the password there are only 47 options.

For the third letter of the password there are only 46 options.

For the fourth letter of the password there are only 45 options.

For the fifth letter of the password there are only 44 options.

For the sixth letter of the password there are only 43 options.

For the seventh letter of the password there are only 42 options.

For the eighth letter of the password there are only 41 options.

To get the number of the possible usernames we multiply the number of options for each letter: 48 x 47 x 46 x 45 x 44 x 43 x 42 x 41 =15214711438080

c) 26 uppercase letters+26 lowercase letters +10digits+12special characters=74 options

i) For the first letter of the password there are 74 options.

For the second letter of the password there are 74 options.

For the third letter of the password there are 74 options.

For the fourth letter of the password there are 74 options.

For the fifth letter of the password there are 74 options.

For the sixth letter of the password there are 74 options.

For the seventh letter of the password there are 74 options.

For the eighth letter of the password there are 74 options.

To get the number of the possible usernames we multiply the number of options for each letter: 74 x 74 x 74 x 74 x 74 x 74 x 74 x 74 =74^8=899194740203776

ii) If letter cannot be repeated.

For the first letter of the password there are 74 options.

For the second letter of the password there are only 73 options.

For the third letter of the password there are only 72 options.

For the fourth letter of the password there are only 71 options.

For the fifth letter of the password there are only 70 options.

For the sixth letter of the password there are only 69 options.

For the seventh letter of the password there are only 68 options.

For the eighth letter of the password there are only 67 options.

To get the number of the possible usernames we multiply the number of options for each letter: 74 x 73 x 72 x 71 x 70 x 69 x 68 x 67 =607681858331520

7 0

3 years ago

QUESTION BELOW PLEASE HELP

Ad libitum [116K]

Answer:

61°

Step-by-step explanation:

180° - 119° = 61°

4 0

3 years ago

What is the square root of 98 round to the nearest tenth?

meriva

The square root of 98 is 9.899<span> so I think if it was rounded to the nearest tenth it would be 9.9</span>

4 0

3 years ago

Read 2 more answers

3) A hat's price was increased by 25%. If the original price was $12.00. How

NISA [10]

Answer:

15 dollers

Step-by-step explanation:

6 0

3 years ago

Read 2 more answers

A nutritionist has developed a diet that she claims will help people lose weight. Twelve people were randomly selected to try th

deff fn [24]

The diet which is developed by the nutritionist is effective at the 0.05 level of significance. Claim is agreed.

<h3>When do we use two-sample t-test?</h3>

The two-sample t-test is used to determine if two population means are equal.

A nutritionist has developed a diet that she claims will help people lose weight. In this,

Twelve people were randomly selected to try the diet.
Their weights were recorded prior to beginning the diet and again after 6 months.

Here are the original weights, in pounds, with the weight after 6 months in parentheses.

Before 192 212 171 215 180 207 165 168 190 184 200 196
After 183 196 174 211 160 191 162 175 190 179 189 195

The mean of the weights before 6 moths is,

$\overline X_1=\dfrac{192+ 212 +171 +215 +180 +207 +165 +168 +190 +184 +200 +196 }{12}\\\overline X_1=190$

The mean of the weights after 6 months is,

$\overline X_2=\dfrac{ 183 +196 +174 +211 +160 +191 +162 +175 +190 +179 +189 +195 }{12}\\\overline X_1=183.75$

Standard deviation of both the data is 16.9 and 14.7.

1. Null and Alternative Hypotheses.

The following null and alternative hypotheses need to be tested:

$\begin{array}{ccl} H_0: \mu_1 & = & \mu_2 \\\\ \\\\ H_a: \mu_1 & > & \mu_2 \end{array}$

This corresponds to a right-tailed test, for which a t-test for two population means, with two independent samples, with unknown population standard deviations will be used.

(2) Rejection Region

Based on the information provided, the significance level is α=0.05 and the degrees of freedom are df = 22. In fact, the degrees of freedom are computed as follows, assuming that the population variances are equal:

$df_{Total} = df_1 + df_2 = 11 + 11 = 22$

Hence, it is found that the critical value for this right-tailed test is

$t_c=1.717$ , for α=0.05 and df=22

The rejection region for this right-tailed test is,

$R = \{t: t > 1.717\}$

(3) Test Statistics

Since it is assumed that the population variances are equal, the t-statistic is computed as follows:

$t = \displaystyle \frac{\bar X_1 - \bar X_2}{\sqrt{ \frac{(n_1-1)s_1^2 + (n_2-1)s_2^2}{n_1+n_2-2}(\frac{1}{n_1}+\frac{1}{n_2}) } }$

$\displaystyle \frac{ 190 - 183.75}{\sqrt{ \frac{(12-1)16.9^2 + (12-1)14.7^2}{ 12+12-2}(\frac{1}{ 12}+\frac{1}{ 12}) } } = 0.967$

(4) Decision about the null hypothesis

Since it is observed that t=0.967≤tc=1.717 it is then concluded that the null hypothesis is not rejected.

Using the P-value approach: The p-value is p=0.1721 and since p=0.1721≥0.05p = 0.1721 it is concluded that the null hypothesis is not rejected.

(5) Conclusion

It is concluded that the null hypothesis H₀ is not rejected. Therefore, there is not enough evidence to claim that the population mean μ1 is greater than μ2, at the α=0.05 significance level.

Confidence Interval

The 95% confidence interval is −7.16<μ<19.66

Thus, the diet which is developed by the nutritionist is effective at the 0.05 level of significance. Claim is agreed.

Learn more about the two-sample t-test here;

brainly.com/question/27198724

#SPJ1

8 0

2 years ago