The distribution of course grades in a very large class is (approximately) Normal with mean 48 and standard deviation 14. The minimum possible grade is 0 and the maximum possible grade is 120. A grade of 90 or more is required to get "A+". The course instructor is considering the possibility of a "bell curve" that will increase the mean grade to 77 and decrease the standard deviation to 6. What is the proportion of students that will get "A+" if the bell curve is applied?

MATLAB: An Introduction with Applications
6th Edition
ISBN:9781119256830
Author:Amos Gilat
Publisher:Amos Gilat
Chapter1: Starting With Matlab
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The distribution of course grades in a very large class is (approximately) Normal with mean 48 and standard deviation
14. The minimum possible grade is 0 and the maximum possible grade is 120. A grade of 90 or more is required to get
"A+". The course instructor is considering the possibility of a "bell curve" that will increase the mean grade to 77 and
decrease the standard deviation to 6. What is the proportion of students that will get "A+" if the bell curve is applied?
Transcribed Image Text:The distribution of course grades in a very large class is (approximately) Normal with mean 48 and standard deviation 14. The minimum possible grade is 0 and the maximum possible grade is 120. A grade of 90 or more is required to get "A+". The course instructor is considering the possibility of a "bell curve" that will increase the mean grade to 77 and decrease the standard deviation to 6. What is the proportion of students that will get "A+" if the bell curve is applied?
N
-3.4
3.3
<<-3.2
3.1
3.0
-2.9
2.8
-2.7
<-2.6
-2.5
<-2.4
<-2.3
<-2.2
<-2.1
<-2.0
-1.9
-1.8
1.7
-1.6
1.5
-1.3
-1.2
-1.1
-1.0
-0.9
-0.8
-0.7
0.6
-0.5
-0.4
-0.3
-0.2
<-0.1
-0.0
.00
.0003
.0005
.0007
.0010
.0013
.0019
.0026
.0035
.0047
.0062
.0082
.0107
.0139
.0179
.0228
.0287
.0359
.0446
.0548
.0668
.0808
.0968
1151
1357
1587
1841
2119
.2420
2743
.3085
.3446
.3821
4207
4602
.5000
.01
.0003
.0005
.0007
.0009
.0013
.0018
.0025
.0034
.0045
.0060
.0080
.0104
.0136
.0174
.0222
.0281
.0351
.0436
.0537
.0655
.0793
.0951
.1131
.1335
.1562
.1814
.2090
2389
.2709
.3050
.3409
.3783
4168
4562
.4960
.02
.0003
.0005
.0006
.0009
.0013
.0018
.0024
.0033
.0044
.0059
.0078
.0102
0132
.0170
.0217
.0274
.0344
.0427
.0526
.0643
.0778
.0934
.1112
.1314
.1539
.1788
2061
2358
.2676
.3015
.3372
.3745
4129
.4522
.4920
.03
.0003
.0004
.0006
.0009
.0012
.0017
.0023
.0032
.0043
.0057
0075
.0099
0129
.0166
.0212
.0268
.0336
.0418
.0516
.0630
.0764
.0918
.1093
.1292
.1515
.1762
.2033
2327
.2643
2981
3336
.3707
4090
4483
.4880
.04
.0003
.0004
.0006
.0008
.0012
.0016
.0023
.0031
.0041
.0055
.0073
.0096
.0125
.0162
0207
.0262
.0329
.0409
.0505
.0618
.0749
.0901
.1075
.1271
1492
1736
.2005
.2296
.2611
.2946
.3300
.3669
4052
.4443
.4840
.05
.0003
.0004
.0006
.0008
.0011
.0016
.0022
.0030
.0040
.0054
.0071
.0094
0122
.0158
.0202
.0256
.0322
.0401
0495
.0606
0735
.0885
.1056
1251
.1469
.1711
.1977
.2266
2578
.2912
.3264
.3632
4013
.4404
.4801
.06
.0003
.0004
.0006
.0008
.0011
.0015
.0021
.0029
.0039
.0052
.0069
.0091
0119
.0154
.0197
.0250
0314
.0392
.0485
0594
.0721
0869
.1038
.1230
.1446
1685
.1949
.2236
.2546
.2877
3228
3594
3974
.4364
.4761
.07
.0003
.0004
.0005
.0008
.0011
.0015
.0021
.0028
.0038
.0051
.0068
.0089
.0116
.0150
.0192
.0244
.0307
.0384
.0475
.0582
.0708
0853
.1020
.1210
.1423
.1660
.1922
.2206
2514
.2843
.3192
.3557
3936
.4325
.4721
.08
.0003
.0004
.0005
.0007
.0010
.0014
.0020
.0027
.0037
.0049
.0066
.0087
.0113
.0146
.0188
.0239
.0301
.0375
.0465
.0571
.0694
.0838
.1003
.1190
.1401
.1635
.1894
2177
.2483
2810
.3156
3520
3897
.4286
.4681
.09
.0002
.0003
.0005
.0007
.0010
.0014
.0019
.0026
.0036
.0048
.0064
.0084
.0110
.0143
.0183
0233
.0294
.0367
.0455
.0559
.0681
.0823
.0985
1170
1379
.1611
1867
2148
.2451
.2776
.3121
.3483
.3859
.4247
4641
Transcribed Image Text:N -3.4 3.3 <<-3.2 3.1 3.0 -2.9 2.8 -2.7 <-2.6 -2.5 <-2.4 <-2.3 <-2.2 <-2.1 <-2.0 -1.9 -1.8 1.7 -1.6 1.5 -1.3 -1.2 -1.1 -1.0 -0.9 -0.8 -0.7 0.6 -0.5 -0.4 -0.3 -0.2 <-0.1 -0.0 .00 .0003 .0005 .0007 .0010 .0013 .0019 .0026 .0035 .0047 .0062 .0082 .0107 .0139 .0179 .0228 .0287 .0359 .0446 .0548 .0668 .0808 .0968 1151 1357 1587 1841 2119 .2420 2743 .3085 .3446 .3821 4207 4602 .5000 .01 .0003 .0005 .0007 .0009 .0013 .0018 .0025 .0034 .0045 .0060 .0080 .0104 .0136 .0174 .0222 .0281 .0351 .0436 .0537 .0655 .0793 .0951 .1131 .1335 .1562 .1814 .2090 2389 .2709 .3050 .3409 .3783 4168 4562 .4960 .02 .0003 .0005 .0006 .0009 .0013 .0018 .0024 .0033 .0044 .0059 .0078 .0102 0132 .0170 .0217 .0274 .0344 .0427 .0526 .0643 .0778 .0934 .1112 .1314 .1539 .1788 2061 2358 .2676 .3015 .3372 .3745 4129 .4522 .4920 .03 .0003 .0004 .0006 .0009 .0012 .0017 .0023 .0032 .0043 .0057 0075 .0099 0129 .0166 .0212 .0268 .0336 .0418 .0516 .0630 .0764 .0918 .1093 .1292 .1515 .1762 .2033 2327 .2643 2981 3336 .3707 4090 4483 .4880 .04 .0003 .0004 .0006 .0008 .0012 .0016 .0023 .0031 .0041 .0055 .0073 .0096 .0125 .0162 0207 .0262 .0329 .0409 .0505 .0618 .0749 .0901 .1075 .1271 1492 1736 .2005 .2296 .2611 .2946 .3300 .3669 4052 .4443 .4840 .05 .0003 .0004 .0006 .0008 .0011 .0016 .0022 .0030 .0040 .0054 .0071 .0094 0122 .0158 .0202 .0256 .0322 .0401 0495 .0606 0735 .0885 .1056 1251 .1469 .1711 .1977 .2266 2578 .2912 .3264 .3632 4013 .4404 .4801 .06 .0003 .0004 .0006 .0008 .0011 .0015 .0021 .0029 .0039 .0052 .0069 .0091 0119 .0154 .0197 .0250 0314 .0392 .0485 0594 .0721 0869 .1038 .1230 .1446 1685 .1949 .2236 .2546 .2877 3228 3594 3974 .4364 .4761 .07 .0003 .0004 .0005 .0008 .0011 .0015 .0021 .0028 .0038 .0051 .0068 .0089 .0116 .0150 .0192 .0244 .0307 .0384 .0475 .0582 .0708 0853 .1020 .1210 .1423 .1660 .1922 .2206 2514 .2843 .3192 .3557 3936 .4325 .4721 .08 .0003 .0004 .0005 .0007 .0010 .0014 .0020 .0027 .0037 .0049 .0066 .0087 .0113 .0146 .0188 .0239 .0301 .0375 .0465 .0571 .0694 .0838 .1003 .1190 .1401 .1635 .1894 2177 .2483 2810 .3156 3520 3897 .4286 .4681 .09 .0002 .0003 .0005 .0007 .0010 .0014 .0019 .0026 .0036 .0048 .0064 .0084 .0110 .0143 .0183 0233 .0294 .0367 .0455 .0559 .0681 .0823 .0985 1170 1379 .1611 1867 2148 .2451 .2776 .3121 .3483 .3859 .4247 4641
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