the of equal width are added to the frequency distribution, as well a for number

ID: 3204429 • Letter: T

Question

the of equal width are added to the frequency distribution, as well a for number of seconds t belong to each class. Table 1.7 is a frequency distributio the mobile phone data in Table 1.6. Table 1.7 Frequency and Relative Frequency Distributions for Completion Times COMPLETION TIMES (IN SECONDs) PERCENT FREQUENCY 220 less than 230 4.5 230 less than 240 7.3 240 less than 250 11.8 250 less than 260 20.0 260 less than 270 29.1 270 less than 280 13 11.8 280 less than 290 290 less than 300 6.4 Table 1.8 is a cumulative frequency distribution and a cumulative perc distribution. Table 1.8 cumulative Frequency and Relative Cumulative Frequency Distributions Completion Times

Explanation / Answer

Solution:

Here, we have to find the mean, variance and standard deviation for the given frequency distribution. The formulas for the mean, variance and standard deviation are given as below:

Mean = µ = FX / F

Variance = F(X - µ)^2 / F

Now, we have to prepare the calculation table which is given as below:

Class

Mid Point X

F*(X - mean)^2

220 to 230

225

1125

6677.867851

230 to 240

235

1880

5637.308562

240 to 250

245

3185

3558.796413

250 to 260

255

5610

942.5585455

260 to 270

265

8480

381.874248

270 to 280

275

3575

2353.306413

280 to 290

285

2850

5501.135703

290 to 300

295

2065

7834.424992

Total

110

28770

32887.27273

Mean =

261.5455